Designation: A 31 – 00

Standard Specification forSteel Rivets and Bars for Rivets, Pressure Vessels 1

This standard is issued under the fixed designation A 31; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon (e) indicates an editorial change since the last revision or reapproval.

1. Scope *

1.1 This specification2 covers steel rivets for use in boilersand pressure vessels and steel bars for use in the manufactureof rivets.

1.2 Two grades are covered:1.2.1 Grade A—Bars having a yield point of 23 000 psi

(160 MPa) minimum with no controls on carbon content.1.2.2 Grade B—Bars having a yield point of 29 000 psi

(200 MPa) minimum with carbon 0.28 % maximum.1.2.3 Rivets are manufactured from the applicable bar

grade.1.3 The values stated in inch-pound units are to be regarded

as the standard. The values given in parentheses are forinformation only.

2. Referenced Documents

2.1 ASTM Standards:A 29/A29M Specification for Steel Bars, Carbon and Alloy,

Hot-Wrought and Cold-Finished, General Requirementsfor3

A 370 Test Methods and Definitions for Mechanical Testingof Steel Products4

A 751 Test Methods, Practices, and Terminology forChemical Analysis of Steel Products4

F 1470 Guide for Fastener Sampling for Specified Mechani-cal Properties and Performance Inspection5

2.2 ANSI/ASME Standards:B18.1.1 Small Solid Rivets7⁄16 Inch Nominal Diameter and

Smaller6

B18.1.2 Large Rivets1⁄2 Inch Nominal Diameter andLarger6

B18.24.1 Part Identifying Number (PIN) Code System7

3. Ordering Information

3.1 Orders for rivets and bars under this specification shallinclude:

3.1.1 ASTM designation and date of issue,3.1.2 Quantity—Number of pieces for rivets and weight for

bars,3.1.3 Name of product and grade (A or B),3.1.4 Size (diameter and length),3.1.5 Rivet head type,3.1.6 If inspection at point of manufacture is required,3.1.7 Certification, if required (Section 14), and3.1.8 Additional testing or special requirements, if required.3.1.9 For establishment of a part identifying system, see

ASME B18.24.1.

NOTE 1—A typical ordering description is: ASTM A 31 – 82, 10 000pieces, steel rivets Grade A,1⁄2 by 2 in., button head, test reports required.

4. Materials and Manufacture

4.1 The steel shall be made by any of the followingprocesses: open-hearth, electric-furnace, or basic-oxygen.

4.2 Rivets shall be manufactured from rivet bars conform-ing to the applicable grade ordered.

4.3 Rivets shall be manufactured by hot- or cold-heading.4.4 Bars shall be furnished as rolled and not pickled, blast

cleaned, or oiled. At producer’s option, bars may be cleaned forinspection or cold drawn.

5. Chemical Composition

5.1 The steel shall conform to chemical composition pre-scribed in Table 1.

5.2 Heat Analysis—An analysis of each heat of steel shallbe made by the bar manufacturer to determine for Grades A andB the percentages of carbon, manganese, phosphorus, andsulfur. This analysis shall be made from a test ingot takenduring the pouring of the heat. The chemical composition thusdetermined shall be reported to the purchaser or his represen-tative and shall conform to the requirements for heat analysisin accordance with Table 1.

5.3 Product Analysis—An analysis may be made by thepurchaser from finished materials representing each heat. Thechemical composition thus determined shall conform to therequirements for product analysis prescribed in Table 1.

1 This specification is under the jurisdiction of ASTM Committee F16 onFasteners and is the direct responsibility of Subcommittee F 16.02 on Steel Bolts,Nuts, Rivets, and Washers.

Current edition approved May 10, 2000. Published July 2000. Originallypublished as A 31 – 01. Last previous edition A 31 – 95.

2 For ASME Boiler and Pressure Vessel Codeapplications see related Specifi-cation SA-31 in Section II of that Code.

3 Annual Book of ASTM Standards,Vol 01.05.4 Annual Book of ASTM Standards,Vol 01.03.5 Annual Book of ASTM Standards, Vol 01.08.6 Available from American National Standards Institute, 11 W. 42nd St., 13th Fl.,

New York, NY 10036.7 Available from American Society of Mechanical Engineers, Three Park

Avenue, New York, NY 10016–5990.

1

*A Summary of Changes section appears at the end of this standard.

Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.

5.4 Application of heats of steel to which bismuth, sele-nium, tellurium, or lead has been intentionally added shall notbe permitted.

5.5 Chemical analyses shall be performed in accordancewith Test Methods A 751.

6. Mechanical Properties

6.1 Rivet Bend Tests:6.1.1 The rivet shank of Grade A steel shall stand being bent

cold through 180° flat on itself, as shown in Fig. 1, withoutcracking on the outside of the bent portion.

6.1.2 The rivet shank of Grade B steel shall stand being bentcold through 180° without cracking on the outside of the bentportion in accordance with Table 2.

6.2 Rivet Flattening Tests—The rivet head shall stand beingflattened, while hot, to a diameter 21⁄2 times the diameter of theshank, as shown in Fig. 2, without cracking at the edges.

6.3 Bar Tensile Properties—Bars shall conform to thetensile requirements in accordance with Table 3.

6.4 Bar Bend Tests:6.4.1 The test specimen for Grade A steel bars shall stand

being bent cold through 180° flat on itself without cracking onthe outside of the bent portion.

6.4.2 The test specimen for Grade B steel bars shall standbeing bent cold through 180° without cracking on the outsideof the bent portion to an inside diameter which shall have arelation to the diameter of the specimen in accordance withTable 4.

7. Dimensions, Mass, and Permissible Variations

7.1 Rivets:7.1.1 The dimensions of rivets shall conform to ANSI

B18.1.2 for nominal diameters in. and larger and B18.1.1 fornominal diameters7⁄16 in. and less.

7.1.2 Snap gage measurement shall be made at the point ofminimum diameter, but it is not required that the rivet shall turncompletely in the gage. Measurements of the maximum toler-ance shall be made with a ring gage, all rivets to slip full to thehead in the gage of the required size for the various diameters.

7.2 Bars—The diameter of hot-finished rivet bars shall notvary from the size specified by more than the amounts inaccordance with Table 5.

8. Workmanship, Finish, and Appearance

8.1 Rivets—The finished rivets shall be true to form, con-centric, and free of injurious defects.

TABLE 1 Chemical Requirements

Grade A Grade B

HeatAnalysis

ProductAnalysis

HeatAnalysis

ProductAnalysis

Carbon, max, % . . . . . . 0.28 0.31Manganese, % 0.30–0.60 0.27–0.63 0.30–0.80 0.27–0.83Phosphorus, max, % 0.040 0.048 0.040 0.048Sulfur, max, % 0.050 0.058 0.050 0.058

FIG. 1 Bend Test of Rivet

TABLE 2 Bend Requirements, Rivets

Diameter ofRivet Shank, in.

Ratio of Bend Diameter to Diameter ofRiver Shank

Grade A Grade B

3⁄4 and underOver 3⁄4

flatflat

111⁄2

FIG. 2 Flattening Test of Rivet

TABLE 3 Tensile Requirements, Bars

Grade A Grade B

Tensile strength, psi (MPa) 45 000–55 000(310–380)

58 000–68 000(400–470)

Yield point, min, psi (MPA) 23 000 (160) 29 000 (200)Elongation in 8 in. or 200

mm, min, %27 22

Elongation in 2 in. or 50mm, min, %

33 25

TABLE 4 Bend Requirements, Bars

Specimen Diameter, in.

Ratio of Bend Diameter to Diameter ofSpecimen

Grade A Grade B

3⁄4 and underOver 3⁄4

flatflat

1⁄21

TABLE 5 Permissible Variations in the Size of Hot-RolledRounds

Specified Size, in.Variations, from Size, in. Out-of-

Round,A in.Over Under

5⁄16 and under 0.005 0.005 0.008Over 5⁄16 to 7⁄16, incl 0.006 0.006 0.009Over 7⁄16 to 5⁄8, incl 0.007 0.007 0.010

Over 5⁄8 to 7⁄8, incl 0.008 0.008 0.012Over 7⁄8 to 1, incl 0.009 0.009 0.013Over 1 to 11⁄8, incl 0.010 0.010 0.015

Over 11⁄8 to 11⁄4, incl 0.011 0.011 0.016Over 11⁄4 to 13⁄8, incl 0.012 0.012 0.018Over 13⁄8 to 11⁄2, incl 0.014 0.014 0.021

A Out-of-round is the difference between the maximum and minimum diametersof the bar, measured at the same cross section.

A 31

2

8.2 Bars:8.2.1 Bars shall be free of visible pipe, undue segregation,

and injurious surface imperfections.8.2.2 Surface Finish—The bars shall have a commercial

hot-wrought finish obtained by conventional hot rolling. See4.4 for producer’s descaling option.

9. Number of Tests and Retests

9.1 Rivets—Sampling for rivet bend and rivet flatteningtests shall be in accordance with Guide F 1470, detectionprocess.

9.2 Bars:9.2.1 Two tension tests shall be made from each heat, unless

the finished material from a heat is less than 50 tons (45 Mg),when one tension test will be sufficient. However, for material2 in. (51 mm) and under in thickness, when the material fromone heat differs3⁄8 in. (9.5 mm) or more in thickness, onetension test shall be made from both the thickest and thethinnest material rolled regardless of the weight represented.Each test shall conform to the specified requirements.

9.2.2 Retests on bars may be made in accordance withSpecification A 29/A 29M.

10. Specimen Preparation

10.1 Rivets—Rivets shall be tested in their full-size finishedcondition.

10.2 Bars:10.2.1 Test specimen selection and preparation shall be in

accordance with Specification A 29/A 29M and Test MethodsA 370.

10.2.2 Tension and bend test specimens for rivet bars whichhave been cold drawn shall be normalized before testing.

11. Test Methods

11.1 Rivets—Rivet bend and flattening tests shall be inaccordance with the manufacturers standard test procedures.

11.2 Bars—Tension and bend tests shall be conducted inaccordance with Test Methods A 370, and especially Supple-ment I thereof, on steel bar products.

12. Inspection

12.1 If the testing described in Section 9 is required by thepurchaser, it shall be specified in the inquiry and contract ororder.

12.2 The inspector representing the purchaser shall havefree entry at all times, while work on the contract of thepurchaser is being performed, to all parts of the manufacturer’sworks that concern the manufacture of the material ordered.The manufacturer shall afford the inspector all reasonablefacilities, without charge, to satisfy him that the material isbeing furnished in accordance with this specification. All tests(except product analysis) and inspection shall be made at theplace of manufacture prior to shipment, unless otherwisespecified, and shall be so conducted as not to interfereunnecessarily with the operation of the works.

13. Rejection and Rehearing

13.1 Rivets—Rivets that fail to conform to the requirementsof this specification may be rejected. Rejection should bereported to the producer or supplier promptly and in writing. Incase of dissatisfaction with the results of the test, the produceror supplier may make claim for a rehearing.

13.2 Bars—Rejection and rehearing shall be in accordancewith Specification A 29/A 29M.

14. Certification

14.1 When specified on the purchase order, the manufac-turer shall furnish certification that the material was manufac-tured and tested in accordance with this specification togetherwith a report of the heat analysis (5.2) and mechanical propertytest results (Section 6) as applicable to the product ordered. Thereport shall include the manufacturer’s name, ASTM designa-tion, grade, heat number (bars only), and authorized signature.

15. Responsibility

15.1 The party responsible for the fastener shall be theorganization that supplies the fastener to the purchaser andcertifies that the fastener was manufactured, sampled, tested,and inspected in accordance with this specification and meetsall of its requirements.

16. Packaging and Package Marking

16.1 Rivets—Rivets shall be properly packed and marked toprevent damage and loss during shipment.

16.2 Bars—Bars shall be packed and marked in accordancewith Specification A 29/A 29M.

17. Keywords

17.1 bars; carbon steel; pressure vessel rivets; rivets; steel

A 31

3

SUMMARY OF CHANGES

This section identifies the location of selected changes to this specification that have been incorporated sincethe –95 issue. For the convenience of the user, Committee F16 has highlighted those changes that may impactthe use of this specification. This section may also include descriptions of the changes or reasons for the changes,or both.

(1) Added 3.1.9, providing for optional use of ASME B18.24.1,Part Identifying Number (PIN) Code System.

The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connectionwith any item mentioned in this standard. Users of this standard are expressly advised that determination of the validity of any suchpatent rights, and the risk of infringement of such rights, are entirely their own responsibility.

This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Headquarters. Your comments will receive careful consideration at a meeting of the responsibletechnical committee, which you may attend. If you feel that your comments have not received a fair hearing you should make yourviews known to the ASTM Committee on Standards, at the address shown below.

This standard is copyrighted by ASTM, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above address or at610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website (www.astm.org).

A 31

4

Designation: A 307 – 03

Standard Specification forCarbon Steel Bolts and Studs, 60 000 PSI Tensile Strength 1

This standard is issued under the fixed designation A 307; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.

This standard has been approved for use by agencies of the Department of Defense.

1. Scope*

1.1 This specification2 covers the chemical and mechanicalrequirements of three grades of carbon steel bolts and studs insizes1⁄4 in. (6.35 mm) through 4 in. (104 mm). The fastenersare designated by “Grade” denoting tensile strength andintended use, as follows:

Grade Description

Grade A Bolts and studs having aminimum tensile strength of

60 ksi (414 MPa) and in-tended for general applica-

tions,Grade B Bolts and studs having a

tensile strength of 60 to 100ksi (414 to 690 MPa) and

intended for flanged joints inpiping systems with cast iron

flanges, andGrade C Nonheaded anchor bolts,

either bent or straight, hav-ing properties conforming toSpecification A 36 (tensile

strength of 58 to 80 ksi (400to 550 MPa)) and intended

for structural anchorage pur-poses.

1.1.1 The termstuds includes stud stock, sometimes re-ferred to asthreaded rod.

1.2 This specification does not cover requirements formachine screws, thread cutting/forming screws, mechanicalexpansion anchors or similar externally threaded fasteners.

1.3 Suitable nuts are covered in Specification A 563. Unlessotherwise specified, the grade and style of nut for each grade offastener, of all surface finishes, shall be as follows:

Fastener Grade and Size Nut Grade and StyleA

A, C, 1⁄4 to 11⁄2 in. A, hexA, C, over 11⁄2 to 4 in. A, heavy hexB, 1⁄4 to 4 in. A, heavy hex

A Nuts of other grades and styles having specified proof load stresses (Speci-

fication A 563, Table 3) greater than the specified grade and style of nut are alsosuitable.

1.4 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.

1.5 Supplementary Requirement S1 of an optional nature isprovided, which describes additional restrictions to be appliedwhen bolts are to be welded. It shall apply only when specifiedin the inquiry, order, and contract.

1.6 Terms used in this specification are defined in Specifi-cation F 1789 unless otherwise defined herein.

2. Referenced Documents

2.1 ASTM Standards:A 36/A 36M Specification for Carbon Structural Steel3

A 153/A 153M Specification for Zinc Coating (Hot-Dip) onIron and Steel Hardware4

A 370 Test Methods and Definitions for Mechanical Testingof Steel Products5

A 563 Specification for Carbon and Alloy Steel Nuts6

A 706/A 706M Specification for Low-Alloy Steel De-formed Bars for Concrete Reinforcement3

A 751 Test Methods, Practices, and Terminology forChemical Analysis of Steel Products5

B 695 Specification for Coatings of Zinc MechanicallyDeposited on Iron and Steel7

D 3951 Practice for Commercial Packaging8

F 606 Test Methods for Determining the Mechanical Prop-erties of Externally and Internally Threaded Fasteners,Washers, and Rivets6

F 1470 Guide for Fastener Sampling for Specified Mechani-cal Properties and Performance Inspection6

F 1789 Terminology for F16 Mechanical Fasteners6

2.2 ANSI/ASME Standards:B 1.1 Unified Screw Threads9

1 This specification is under the jurisdiction of ASTM Committee F16 onFasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts,Nuts, Rivets, and Washers.

Current edition approved Oct. 1, 2003. Published October 2003. Originallyapproved in 1947. Last previous edition approved in 2002 as A 307 – 02.

2 For ASME Boiler and Pressure Vessel Codeapplications see related Specifi-cation SA-307 in Section II of that Code.

3 Annual Book of ASTM Standards,Vol 01.04.4 Annual Book of ASTM Standards,Vol 01.06.5 Annual Book of ASTM Standards,Vol 01.03.6 Annual Book of ASTM Standards,Vol 01.08.7 Annual Book of ASTM Standards,Vol 02.05.8 Annual Book of ASTM Standards, Vol 15.09.9 Available from American National Standards Institute (ANSI), 25 W. 43rd St.,

4th Floor, New York, NY 10036.

1

*A Summary of Changes section appears at the end of this standard.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

B 18.2.1 Square and Hex Bolts and Screws9

B 18.24.1 Part Identifying Number (PIN) Code System10

2.3 Military Standard:MIL-STD 105 Single Sampling Plan for Normal Inspec-

tion11

3. Ordering Information

3.1 Orders for externally threaded fasteners (including nutsand accessories) under this specification shall include thefollowing:

3.1.1 ASTM designation and year of issue,3.1.2 Name of product, bolts or studs; and bolt head style,

that is, hex or heavy hex,3.1.3 Grade, that is, A, or B, or C. If no grade is specified,

Grade A is furnished.3.1.4 Quantities (number of pieces by size including nuts),3.1.5 Fastener size and length,3.1.6 Washers—Quantity and size (separate from bolts),3.1.7 Zinc Coating—Specify the zinc-coating process re-

quired, for example, hot-dip, mechanically deposited, or nopreference (see 4.5).

3.1.8 Other Finishes—Specify other protective finish, ifrequired.

3.1.9 Specify if inspection at point of manufacture is re-quired,

3.1.10 Specify if certified test report is required (see 8.2),and

3.1.11 Specify additional testing (8.3) or special require-ments.

3.1.12 For establishment of a part identifying system, seeANSI/ASME B18.24.1.

4. Materials and Manufacture

4.1 Steel for bolts and studs shall be made by the open-hearth, basic-oxygen, or electric-furnace process.

4.2 Bolts shall be produced by hot or cold forging of theheads or machining from bar stock.

4.3 Heat Treatment:4.3.1 Cold headed fasteners with head configurations other

than hex shall be stress relief annealed.4.3.2 Stress relieving of hex head fasteners shall be at the

manufacturer’s option.4.4 Bolt and stud threads shall be rolled or cut.4.5 Zinc Coatings, Hot-Dip and Mechanically Deposited:4.5.1 When zinc-coated fasteners are required, the pur-

chaser shall specify the zinc-coating process, for example hotdip, mechanically deposited, or no preference.

4.5.2 When hot-dip is specified, the fasteners shall bezinc-coated by the hot-dip process in accordance with therequirements of Class C of Specification A 153.

4.5.3 When mechanically deposited is specified, the fasten-ers shall be zinc-coated by the mechanical-deposition processin accordance with the requirements of Class 50 of Specifica-tion B 695.

4.5.4 When no preference is specified, the supplier mayfurnish either a hot-dip zinc coating in accordance withSpecification A 153, Class C or a mechanically deposited zinccoating in accordance with Specification B 695, Class 50.Threaded components (bolts and nuts) shall be coated by thesame zinc-coating process and the supplier’s option is limitedto one process per item with no mixed processes in a lot.

5. Chemical Composition

5.1 Grade A and B bolts and studs shall have a heat analysisconforming to the requirements specified in Table 1 based onthe steel producer’s heat analysis.

5.2 The purchaser shall have the option of conductingproduct analyses on finished bolts in each lot, which shallconform to the product analysis specified in Table 1.

5.3 In case of conflict or for referee purposes, the productanalysis shall take precedence.

5.4 Bolts and studs are customarily furnished from stock, inwhich case individual heats of steel cannot be identified.

5.5 Application of heats of steel to which bismuth, sele-nium, tellurium, or lead has been intentionally added shall notbe permitted for Grade B bolts and studs.

5.6 Chemical analyses shall be performed in accordancewith Test Methods, Practices, and Terminology A 751.

6. Mechanical Properties

6.1 Grades A and B bolts and studs shall conform to thehardness specified in Table 2.

6.2 Grade A and B bolts and studs 1½ in. in diameter or less,other than those excepted in 6.4, shall be tested full size andshall conform to the requirements for tensile strength specifiedin Table 3.

6.3 Grade A and B bolts and studs larger than 1½ in. indiameter, other than those excepted in 6.4, shall preferably betested full size and when equipment of sufficient capacity isavailable and shall conform to the requirements for tensilestrength specified in Table 3. When equipment of sufficientcapacity for full-size bolt testing is not available, or when thelength of the bolt makes full-size testing impractical, machinedspecimens shall be tested and shall conform to the require-ments specified in Table 4.

6.4 Grades A and B bolts and studs less than three diametersin length or bolts with drilled or undersize heads are not subjectto tensile tests.

6.5 Grade C nonheaded anchor bolts shall be tested usingmachined specimens and shall conform to the tensile propertiesspecified for bars in Specification A 36/A 36M. Properties are

10 Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990.

11 Available from Standardization Documents Order Desk, Bldg. 4 Section D,700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.

TABLE 1 Chemical Requirements for Grades A and B Bolts andStuds

Heat Analysis Product AnalysisCarbon, max 0.29 0.33Manganese, max 0.90 0.93Phosphorus, max 0.04 0.041Sulfur, max

Grade A 0.15 A

Grade B 0.05 0.051A Resulfurized steel is not subject to rejection based on product analysis for

sulfur.

A 307 – 03

2

shown in Table 4 for information. In the event of conflictSpecification A 36/A 36M shall control.

6.6 In the event that bolts are tested by both full size and bymachine test specimen methods, the full-size test shall governif a controversy between the two methods exists.

6.7 For bolts and studs on which both hardness and tensiontests are performed, acceptance based on tensile requirementsshall take precedence in the event that there is controversy overlow readings of hardness tests.

7. Dimensions

7.1 Unless otherwise specified, threads shall be the CoarseThread Series as specified in the latest issue of ANSI/ASMEB1.1, and shall have a Class 2A tolerance.

7.2 Unless otherwise specified, Grade A bolts shall be hexbolts with dimensions as given in the latest issue of ANSI/ASME B18.2.1. Unless otherwise specified, Grade B boltsshall be heavy hex bolts with dimensions as given in the latestissue of ANSI/ASME B18.2.1.

7.3 Unless otherwise specified, bolts and studs to be usedwith nuts or tapped holes which have been tapped oversize, inaccordance with Specification A 563, shall have Class 2Athreads before hot-dip or mechanically deposited zinc coating.After zinc coating the maximum limit of pitch and majordiameter shall not exceed the Class 2A maximum limit by morethan the following amounts:

Diameter, in. Oversize Limit, in. (mm)A1⁄4 0.0165⁄16 , 3⁄8 0.0177⁄16 , 1⁄2 0.0189⁄16 to 3⁄4 , incl 0.0207⁄8 0.0221.0 to 11⁄4 , incl 0.02413⁄8 , 11⁄2 0.02713⁄4 to 4.0, incl 0.050

A These values are the same as the overtapping required for zinc-coated nuts inSpecification A 563.

7.4 The gaging limit for bolts and studs shall be verifiedduring manufacture or use by assembly of a nut tapped asnearly as practical to the amount oversize shown above. In caseof dispute, a calibrated thread ring gage of that same size(Class X tolerance, gage tolerance plus) shall be used. Assem-bly of the gage, or the nut described above, must be possiblewith hand effort following application of light machine oil toprevent galling and damage to the gage. These inspections,when performed to resolve disputes, shall be performed at thefrequency and quality described in Table 5.

TABLE 2 Hardness Requirements for Bolts and Studs

Grade Length, in.0

HardnessA

Brinell Rockwell B

min max min max

A Less than 3 3 diaB 121 241 69 1003 3 dia and longer . . . 241 . . . 100

B Less than 3 3 diaB 121 212 69 953 3 dia and longer . . . 212 . . . 95

C All No hardness requiredA As measured anywhere on the surface or through the cross section.B Also bolts with drilled or undersize heads. These sizes and bolts with modified

heads shall meet the minimum and maximum hardness as hardness is the onlyrequirement.

TABLE 3 Tensile Requirements for Full-Size Bolts and Studs

BoltSize,

in.

Threadsper inch

StressArea,A

in.2

Tensile Strength, lbfB

GradeA, minC

Grade B

minD maxD

1⁄4 20 0.0318 1 900 1 900 3 1805⁄16 18 0.0524 3 100 3 100 5 2403⁄8 16 0.0775 4 650 4 650 7 7507⁄16 14 0.1063 6 350 6 350 10 630

1⁄2 13 0.1419 8 500 8 500 14 1909⁄16 12 0.182 11 000 11 000 18 2005⁄8 11 0.226 13 550 13 550 22 6003⁄4 10 0.334 20 050 20 050 33 4007⁄8 9 0.462 27 700 27 700 46 200

1 8 0.606 36 350 36 350 60 60011⁄8 7 0.763 45 800 45 800 76 30011⁄4 7 0.969 58 150 58 150 96 90013⁄8 6 1.155 69 300 69 300 115 500

11⁄2 6 1.405 84 300 84 300 140 50013⁄4 5 1.90 114 000 114 000 190 0002 4½ 2.50 150 000 150 000 250 00021⁄4 4½ 3.25 195 000 195 000 325 000

21⁄2 4 4.00 240 000 240 000 400 00023⁄4 4 4.93 295 800 295 800 493 0003 4 5.97 358 200 358 200 597 00031⁄4 4 7.10 426 000 426 000 710 000

31⁄2 4 8.33 499 800 499 800 833 00033⁄4 4 9.66 579 600 579 600 966 0004 4 11.08 664 800 664 800 1 108 000

A Area calculated from the equation:As= 0.7854 [D − (0.9743/n)]

2

where:

As = stress area,D = nominal diameter of bolt, andn = threads per inch.

B 1 lbf = 4.448 N.C Based on 60 ksi (414 MPa).D Based on 60–100 ksi (414–690 MPa).

TABLE 4 Tensile Requirements for Machined Specimens

Grade A Grade B Grade C

Tensile strength, ksi 60 min 60–100 58–80Yield point, min ksi . . . . . . 36Elongation in 2 in.,min, %

18 18 23

TABLE 5 Sample Sizes and Acceptance Numbers for Inspectionof Hot-Dip or Mechanically Deposited Zinc-Coated Threads

Lot Size Sample SizeA,B Acceptance NumberA

2 to 90 13 191 to 150 20 2151 to 280 32 3281 to 500 50 5

501 to 1 200 80 71 201 to 3 200 125 10

3 201 to 10 000 200 1410 001 and over 315 21

A Sample sizes of acceptance numbers are extracted from “Single SamplingPlan for Normal Inspection,” Table IIA, MIL-STD-105.

B Inspect all bolts in the lot if the lot size is less than the sample size.

A 307 – 03

3

8. Number of Tests and Retests

8.1 The requirements of this specification shall be met incontinuous mass production for stock, and the manufacturershall make sample inspections to ensure that the productconforms to the specified requirements. Additional tests ofindividual shipments of material are not ordinarily contem-plated. Individual heats of steel are not identified in the finishedproduct.

8.2 When specified in the order, the manufacturer shallfurnish a test report certified to be the last completed set ofmechanical tests for each stock size in each shipment.

8.3 When additional tests are specified on the purchaseorder, a lot, for purposes of selecting test samples, shall consistof all material offered for inspection at one time that has thefollowing common characteristics:

8.3.1 One type of item,8.3.2 One nominal size, and8.3.3 One nominal length of bolts and studs.8.4 From each lot, the number of tests for each requirement

shall be as follows:Number of Pieces in Lot Number of Samples

800 and under 1801 to 8 000 28 001 to 22 000 3Over 22 000 5

8.5 If any machined test specimen shows defective machin-ing it shall be discarded and another specimen substituted.

8.6 Should any sample fail to meet the requirements of aspecified test, double the number of samples from the same lotshall be tested, in which case all of the additional samples shallmeet the specification.

9. Test Methods

9.1 Grades A and B bolts and studs shall be tested inaccordance with Test Methods F 606.

9.2 Grade C nonheaded anchor bolts shall have machinedspecimen tension tests made on the bolt body or on the barstock used for making the anchor bolts. Tests on finishedanchor bolts shall be made in accordance with Test MethodsF 606 and tests on bar stock in accordance with SpecificationA 36/A 36M and Test Methods A 370.

9.3 Standard square and hex head bolts only shall be testedby the wedge tension method except as noted in 6.4. Fractureshall be in the body or threads of the bolt without any fractureat the junction of the head and body. Other headed bolts shallbe tested by the axial tension method.

9.4 Speed of testing as determined with a free runningcrosshead shall be a maximum of 1 in. (25.4 mm)/min for thetensile strength tests of bolts.

10. Inspection

10.1 If the inspection described in 10.2 is required by thepurchaser it shall be specified in the inquiry, order, or contract.

10.2 The inspector representing the purchaser shall havefree entry to all parts of the manufacturer’s works that concernthe manufacture of the material ordered. The manufacturershall afford the inspector all reasonable facilities to satisfy himthat the material is being furnished in accordance with thisspecification. All tests and inspections required by the specifi-

cation that are requested by the purchaser’s representative shallbe made before shipment, and shall be conducted as not tointerfere unnecessarily with the operation of the works.

11. Responsibility

11.1 The party responsible for the fastener shall be theorganization that supplies the fastener to the purchaser andcertifies that the fastener was manufactured, sampled, testedand inspected in accordance with this specification and meetsall of its requirements.

12. Rejection and Rehearing

12.1 Disposition of nonconforming lots shall be in accor-dance with Guide F 1470, specifically sections on dispositionof nonconforming lots, suppliers option, and purchasers option.

13. Product Marking

13.1 Grades A and B Bolts and Studs:13.1.1 Bolt heads and one end of studs shall be marked with

a unique identifier by the manufacturer to identify the manu-facturer or private label distributor, as appropriate. Additionalmarking required by the manufacturer for his own use shall beat the option of the manufacturer.

13.1.2 In addition to the requirements of 13.1, all bolt heads,one end of studs" in. and larger, and whenever feasible studsless than" in. shall be marked with a grade marking asfollows:

Grade MarkingAB

307A307B

13.1.3 All markings shall be located on the top of the bolthead or stud end and shall be raised or depressed at the optionof the manufacturer.

13.2 Grade C Anchor Bolts:13.2.1 The end of Grade C anchor bolts intended to project

from the concrete shall be color coded green.13.2.2 When permanent marking of manufacturer’s identi-

fication and grade identification is required, SupplementaryRequirements S2 and S3 shall be specified.

13.3 Grade and manufacturer’s or private label distributor’sidentification shall be separate and distinct. The two identifi-cations shall preferably be in different locations and, when onthe same level, shall be separated by at least two spaces.

14. Packaging and Package Marking

14.1 Packaging:14.1.1 Unless otherwise specified, packaging shall be in

accordance with Practice D 3951.14.1.2 When special packaging requirements are required,

they shall be defined at the time of the inquiry and order.14.2 Package Marking:14.2.1 Each shipping unit shall include or be plainly marked

with the following information:14.2.1.1 ASTM designation and grade,14.2.1.2 Size,14.2.1.3 Name and brand or trademark of the manufacturer,14.2.1.4 Number of pieces,14.2.1.5 Purchase order number,14.2.1.6 Country of origin.

A 307 – 03

4

15. Keywords15.1 bolts; carbon steel; steel; studs

SUPPLEMENTARY REQUIREMENTS

The following supplementary requirement shall apply only when specified in the purchase order orcontract:

S1. Bolts Suitable for Welding

S1.1 The material described in this section is intended forwelding. This supplemental section, by additional chemicalcomposition restrictions and by a carbon equivalent formula,provides assurance of weldability by chemical compositioncontrol.

S1.2 Welding technique is of fundamental importance whenbolts produced to this supplementary section are welded. It ispresupposed that suitable welding procedures for the steelbeing welded and the intended service will be selected.

S1.3 All of the requirements of this supplemental sectionapply in addition to all of the chemical, mechanical, and otherrequirements of the base specification, Specification A 307 forGrade B.

S1.4 Because of the embrittling effects of welding tempera-tures on cold-forged steel, this supplemental section is limitedto hot-forged bolts, or, if not forged, then to bolts producedfrom hot-rolled bars without forging or threaded bars, barsstuds, or stud bolts produced from hot-rolled bars withoutforging. Cold-forged bolts, or cold-drawn threaded bars, if theyare given a thermal treatment by heating to a temperature of notless than 1500°F (815°C) and air-cooled are also suitable.

S1.5 Chemical Requirements:S1.5.1 Heat Chemical Analysis—Material conforming to

the following additional analysis limitations shall be used tomanufacture the product described in this supplementaryrequirement.

Carbon 0.30 %, maxManganese 1.00 %, maxPhosphorus 0.04 %, maxSulfur 0.05 %, maxSilicon 0.50 %, max

S1.5.2 Carbon Equivalent (Source—Specification A 706/A 706M)—In addition to the heat chemical analysis require-ments in S1.5.1, the heat analysis shall be such as to provide a

carbon equivalent (CE) not exceeding 0.55 when calculated asfollows:CE = % C +

% Mn6 1

% Cu40 1

% Ni20 1

% Cr10 2

% Mo50 2

% V10

S1.6 Analysis Reports—If requested on the order or con-tract, the chemical composition of each heat of steel used andthe calculated carbon equivalent for each heat shall be reportedto the purchaser.

S1.7 Product (Check) Verification Analysis—Chemicalanalyses when made by the purchaser or a representative onbolts from each heat of steel, shall not exceed the valuesspecified in S1.5.2 by more than the following amounts:

%Carbon +0.03Manganese +0.06Phosphorus +0.008Sulfur +0.008Silicon +0.05

S2. Permanent Manufacturer’s Identification

S2.1 The end of the anchor bolt intended to project from theconcrete shall be steel die stamped with the manufacturer’sidentification.

NOTE —For marking small sizes, customarily less than" in., consultthe anchor bolt manufacturer for the minimum size capable of beingmarked.

S3. Permanent Grade Identification

S3.1 The end of the anchor bolt intended to project from theconcrete shall be steel die stamped with the Grade identifica-tion “307C”.

S3.2 The requirements in S2.1 for marking small sizes shallalso apply to Supplementary Requirement S3.

A 307 – 03

5

SUMMARY OF CHANGES

This section identifies the location of selected changes to this standard that have been incorporated since theA 307 – 02 issue. For the convenience of the user, Committee F16 has highlighted those changes that impact theuse of this standard. This section may also include descriptions of the changes or reasons for the changes, or both.(Approved Oct. 1, 2003.)

(1) Added Section 1.6 that references Terminology F 1789for definitions of terms.

This section identifies the location of selected changes to this standard that have been incorporated since the A 307 – 00 issue.For the convenience of the user, Committee F16 has highlighted those changes that impact the use of this standard. Thissection may also include descriptions of the changes or reasons for the changes, or both. (Approved October 10, 2002.)

(1) Deleted the metric units from Table 4. (2) Corrected the carbon equivalent formula for nickel inS1.5.2.

ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.

This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.

This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website(www.astm.org).

A 307 – 03

6

Designation: A 325 – 04 American AssociationState Highway andTransportation Officials

Standard AASHTO No.: M 164

Standard Specification forStructural Bolts, Steel, Heat Treated, 120/105 ksi MinimumTensile Strength 1

This standard is issued under the fixed designation A 325; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.

This standard has been approved for use by agencies of the Department of Defense.

1. Scope*

1.1 This specification2 covers two types of quenched andtempered steel heavy hex structural bolts having a minimumtensile strength of 120 ksi for sizes 1.0 in. and less and 105 ksifor sizes over 1.0 to 11⁄2 in., inclusive.

1.2 The bolts are intended for use in structural connections.These connections are covered under the requirements of theSpecification for Structural Joints Using ASTM A 325 or A 490Bolts, approved by the Research Council on Structural Con-nections, endorsed by the American Institute of Steel Construc-tion and by the Industrial Fastener Institute.3

1.3 The bolts are furnished in sizes1⁄2 to 11⁄2 in., inclusive.They are designated by type, denoting chemical composition asfollows:Type Description

Type 1 Medium carbon, carbon boron, or medium carbon alloy steel.Type 2 Withdrawn in November 1991.Type 3 Weathering steel.

NOTE 1—Bolts for general applications, including anchor bolts, arecovered by Specification A 449. Also refer to Specification A 449 forquenched and tempered steel bolts and studs with diameters greater than11⁄2 in. but with similar mechanical properties.

NOTE 2—A complete metric companion to Specification A 325 hasbeen developed—Specification A 325M; therefore, no metric equivalentsare presented in this specification.

1.4 This specification is applicable to heavy hex structuralbolts only. For bolts of other configurations and thread lengthswith similar mechanical properties, see Specification A 449.

1.5 Terms used in this specification are defined in Specifi-cation F 1789.

1.6 The following safety hazards caveat pertains only tothe test methods portion, Section 10, of this specification:This

standard does not purport to address all of the safety concerns,if any, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.

2. Referenced Documents

2.1 ASTM Standards:4

A 153 Specification for Zinc Coating (Hot-Dip) on Iron andSteel Hardware

A 194/A 194M Specification for Carbon and Alloy SteelNuts for Bolts for High Pressure or High TemperatureService, or Both

A 449 Specification for Quenched and Tempered SteelBolts and Studs

A 490 Specification for Structural Bolts, Alloy Steel, HeatTreated, 150 ksi Minimum Tensile Strength

A 563 Specification for Carbon and Alloy Steel NutsA 751 Test Methods, Practices, and Terminology for

Chemical Analysis of Steel ProductsB 695 Specification for Coatings of Zinc Mechanically

Deposited on Iron and SteelD 3951 Practice for Commercial PackagingF 436 Specification for Hardened Steel WashersF 606 Test Methods for Determining the Mechanical Prop-

erties of Externally and Internally Threaded Fasteners,Washers, and Rivets

F 788/F 788M Specification for Surface Discontinuities ofBolts, Screws, and Studs, Inch and Metric Series

F 959 Specification for Compressible-Washer-Type DirectTension Indicators for Use with Structural Fasteners

F 1470 Guide for Fastener Sampling for Specified Mechani-cal Properties and Performance Inspection

F 1789 Terminology for F16 Mechanical FastenersG 101 Guide for Estimating the Atmospheric Corrosion

Resistance of Low-Alloy Steels1 This specification is under the jurisdiction of ASTM Committee F16 on

Fasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts,Nuts, Rivets, and Washers.

Current edition approved Jan. 1, 2004. Published January 2004. Originallyapproved in 1964. Last previous edition approved in 2002 as A 325 – 02.

2 For ASME Boiler and Pressure Vessel Codeapplications see related Specifi-cation SA-325 in Section II of that Code.

3 Published by American Institute of Steel Construction,One East Wacker Dr.,Ste. 3100, Chicago, IL 60601-2001.

4 For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service@astm.org. ForAnnual Book of ASTMStandardsvolume information, refer to the standard’s Document Summary page onthe ASTM website.

1

*A Summary of Changes section appears at the end of this standard.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

2.2 ASME Standards:5

B 1.1 Unified Screw ThreadsB 18.2.6 Fasteners for Use in Structural ApplicationsB 18.24.1 Part Identifying Number (PIN) Code System2.3 Military Standard:6

MIL-STD-105 Sampling Procedure and Tables for Inspec-tion by Attributes

3. Ordering Information

3.1 Orders for heavy hex structural bolts under this speci-fication shall include the following:

3.1.1 Quantity (number of pieces of bolts and accessories).3.1.2 Size, including nominal bolt diameter, thread pitch,

and bolt length.3.1.3 Name of product, heavy hex structural bolts.3.1.4 When bolts threaded full length are required, Supple-

mentary Requirement S1 shall be specified.3.1.5 Type of bolt: Type 1 or 3. When type is not specified,

either Type 1 or Type 3 shall be furnished at the supplier’soption.

3.1.6 ASTM designation and year of issue.3.1.7 Other components such as nuts, washers, and com-

pressible washer-type direct-tension indicators, if required.3.1.7.1 When such other components are specified to be

furnished, also state “Nuts, washers, and direct tension indica-tors, or combination thereof, shall be furnished by lot number.”

3.1.8 Zinc Coating—Specify the zinc coating process re-quired, for example, hot dip, mechanically deposited, or nopreference (see 4.3).

3.1.9 Other Finishes—Specify other protective finish, ifrequired.

3.1.10 Test reports, if required (see Section 13).3.1.11 Supplementary or special requirements, if required.3.1.12 For establishment of a part identifying system, see

ASME B18.24.1.

NOTE 3—A typical ordering description follows: 1000 pieces 11⁄8-7UNC in. dia 3 4 in. long heavy hex structural bolt,Type 1 ASTMA 325–02, each with one hardened washer, ASTM F 436 Type 1, and oneheavy hex nut, ASTM A 563 Grade DH. Each component hot-dipzinc-coated. Nuts lubricated.

3.2 Recommended Nuts:3.2.1 Nuts conforming to the requirements of Specification

A 563 are the recommended nuts for use with SpecificationA 325 heavy hex structural bolts. The nuts shall be of the classand have a surface finish for each type of bolt as follows:

Bolt Type and Finish Nut Class and Finish

1, plain (noncoated) A 563-C, C 3, D, DH, DH3,plain

1, zinc coated A 563-DH, zinc coated3, plain A 563-C3, DH3, plain

3.2.2 Alternatively, nuts conforming to Specification A 194/A 194M Gr. 2H are considered a suitable substitute for usewith Specification A 325 Type 1 heavy hex structural bolts.

3.2.3 When Specification A 194/A 194M Gr. 2H zinc-coated nuts are supplied, the zinc coating, overtapping, lubri-cation, and rotational capacity testing shall be in accordancewith Specification A 563.

3.3 Recommended Washers:3.3.1 Washers conforming to Specification F 436 are the

recommended washers for use with Specification A 325 heavyhex structural bolts. The washers shall have a surface finish foreach type of bolt as follows:

Bolt Type and Finish Washer Finish

1, plain (uncoated) plain (uncoated)1, zinc coated zinc coated3, plain weathering steel, plain

3.4 Other Accessories:3.4.1 When compressible washer type direct tension indica-

tors are specified to be used with these bolts, they shallconform to Specification F 959 Type 325.

4. Materials and Manufacture

4.1 Heat Treatment:4.1.1 Type 1 bolts produced from medium carbon steel shall

be quenched in a liquid medium from the austenitizingtemperature. Type 1 bolts produced from medium carbon steelto which chromium, nickel, molybdenum, or born were inten-tionally added shall be quenched only in oil from the austen-itizing temperature.

4.1.2 Type 3 bolts shall be quenched only in oil from theaustenitizing temperature.

4.1.3 Type 1 bolts, regardless of the steel used, and Type 3bolts shall be tempered by reheating to not less than 800°F.

4.2 Threading—Threads shall be cut or rolled.4.3 Zinc Coatings, Hot-Dip and Mechanically Deposited:4.3.1 When zinc-coated fasteners are required, the pur-

chaser shall specify the zinc coating process, for example, hotdip, mechanically deposited, or no preference.

4.3.2 When hot-dip is specified, the fasteners shall bezinc-coated by the hot-dip process and the coating shallconform to the coating weight/thickness and performancerequirements of Class C of Specification A 153.

4.3.3 When mechanically deposited is specified, the fasten-ers shall be zinc-coated by the mechanical deposition processand the coating shall conform to the coating weight/thicknessand performance requirements of Class 50 of SpecificationB 695.

4.3.4 When no preference is specified, the supplier shallfurnish either a hot-dip zinc coating in accordance withSpecification A 153, Class C, or a mechanically deposited zinccoating in accordance with Specification B 695, Class 50.Threaded components (bolts and nuts) shall be coated by thesame zinc-coating process and the supplier’s option is limitedto one process per item with no mixed processes in a lot.

4.4 Lubrication—When zinc-coated nuts are ordered withthe bolts, the nuts shall be lubricated in accordance withSpecification A 563, Supplementary Requirement S1, to mini-mize galling.

4.5 Secondary Processing:

5 Available from ASME International, Information Central, 22 Law Dr., PO Box2300, Fairfield, NJ 07007-2300

6 Available from USA Information Systems, Inc., 1092 Laskin Rd., Ste. 208,Virginia Beach, VA 23451.

A 325 – 04

2

4.5.1 If any processing, which can affect the mechanicalproperties or performance of the bolts, is performed after theinitial testing, the bolts shall be retested for all specifiedmechanical properties and performance requirements affectedby the reprocessing.

4.5.2 When the secondary process is heat treatment, thebolts shall be tested for all specified mechanical properties. Hotdip zinc-coated bolts shall be tested for all specified mechani-cal properties and rotational capacity. If zinc-coated nuts arerelubricated after the initial rotational capacity tests, theassemblies shall be retested for rotational capacity.

5. Chemical Composition

5.1 Type 1 bolts shall be plain carbon steel, carbon boronsteel, alloy steel or alloy boron steel at the manufacturer’soption, conforming to the chemical composition specified inTable 1.

5.2 Type 3 bolts shall be weathering steel and shall conformto one of the chemical compositions specified in Table 2. Theselection of the chemical composition, A, B, C, D, E, or F, shallbe at the option of the bolt manufacturer. See Guide G 101 formethods of estimating the atmospheric corrosion resistance oflow alloy steels.

5.3 Product analyses made on finished bolts representingeach lot shall conform to the product analysis requirementsspecified in Table 1 and Table 2, as applicable.

5.4 Heats of steel to which bismuth, selenium, tellurium, orlead has been intentionally added shall not be permitted forbolts.

5.5 Compliance with 5.4 shall be based on certification thatheats of steel having any of the listed elements intentionallyadded were not used to produce the bolts.

5.6 Chemical analyses shall be performed in accordancewith Test Methods, Practices, and Terminology A 751.

6. Mechanical Properties

6.1 Hardness—The bolts shall conform to the hardnessspecified in Table 3.

6.2 Tensile Properties:6.2.1 Except as permitted in 6.2.2 for long bolts and 6.2.3

for short bolts, sizes 1.00 in. and smaller having a length of 21⁄4D and longer, and sizes larger than 1.00 in. having a length of3D and longer, shall be wedge tested full size and shallconform to the minimum wedge tensile load and proof load oralternative proof load specified in Table 4. The load achievedduring proof load testing shall be equal to or greater than thespecified proof load.

6.2.2 When the length of the bolt makes full-size testingimpractical, machined specimens shall be tested and shallconform to the requirements specified in Table 5. When boltsare tested by both full-size and machined specimen methods,the full-size test shall take precedence.

6.2.3 Sizes 1.00 in. and smaller having a length shorter than21⁄4 D down to 2D, inclusive, that cannot be wedge tensiletested shall be axially tension tested full size and shall conformto the minimum tensile load and proof load or alternate proofload specified in Table 4. Sizes 1.00 in. and smaller having alength shorter than 2D that cannot be axially tensile tested shallbe qualified on the basis of hardness.

6.2.4 For bolts on which both hardness and tension tests areperformed, acceptance based on tensile requirements shall takeprecedence in the event of low hardness readings.

6.3 Rotational Capacity Test:6.3.1 Definition—The rotational capacity test is intended to

evaluate the presence of a lubricant, the efficiency of thelubricant, and the compatibility of assemblies as represented bythe components selected for testing.

6.3.2 Requirement—Zinc-coated bolts, zinc-coated wash-ers, and zinc-coated and lubricated nuts tested full size in anassembled joint or tension measuring device, in accordancewith 10.2, shall not show signs of failure when subjected to thenut rotation in Table 6. The test shall be performed by theresponsible party (see Section 14) prior to shipment after zinccoating and lubrication of nuts (see 10.2 and Note 5).

TABLE 1 Chemical Requirements for Type 1 Bolts

ElementCarbon Steel

HeatAnalysis

ProductAnalysis

Carbon 0.30–0.52 0.28–0.55Manganese, min 0.60 0.57Phosphorus, max 0.040 0.048Sulfur, max 0.050 0.058Silicon 0.15–0.30 0.13–0.32

ElementCarbon Boron Steel

HeatAnalysis

ProductAnalysis

Carbon 0.30–0.52 0.28–0.55Manganese, min 0.60 0.57Phosphorus, max 0.040 0.048Sulfur, max 0.050 0.058Silicon 0.10–0.30 0.08–0.32Boron 0.0005–0.003 0.0005–0.003

ElementAlloy Steel

HeatAnalysis

ProductAnalysis

Carbon 0.30–0.52 0.28–0.55Manganese, min 0.60 0.57Phosphorus, max 0.035 0.040Sulfur, max 0.040 0.045Silicon 0.15–0.35 0.13–0.37Alloying Elements A A

Alloy Boron Steel

HeatAnalysis

ProductAnalysis

Carbon 0.30–0.52 0.28–0.55Manganese, min 0.60 0.57Phosphorus, max 0.035 0.040Sulfur, max 0.040 0.045Silicon 0.15–0.35 0.13–0.37Boron 0.0005–0.003 0.0005–0.003Alloying Elements A A

A Steel, as defined by the American Iron and Steel Institute, shall be consideredto be alloy when the maximum of the range given for the content of alloyingelements exceeds one or more of the following limits: Manganese, 1.65 %; silicon,0.60 %; copper, 0.60 % or in which a definite range or a definite minimum quantityof any of the following elements is specified or required within the limits of therecognized field of constructional alloy steels: aluminum, chromium up to 3.99 %,cobalt, columbium, molybdenum, nickel, titanium, tungsten, vanadium, zirconium,or any other alloying elements added to obtain a desired alloying effect.

A 325 – 04

3

6.3.3 Acceptance Criterion—The bolt and nut assemblyshall be considered as non-conforming if the assembly fails topass any one of the following specified requirements:

6.3.3.1 Inability to install the assembly to the nut rotation inTable 6.

6.3.3.2 Inability to remove the nut after installing to therotation specified in Table 6.

6.3.3.3 Shear failure of the threads as determined by visualexamination of bolt and nut threads following removal.

6.3.3.4 Torsional or torsional/tension failure of the bolt.Elongation of the bolt, in the threads between the nut and bolthead, is to be expected at the required rotation and is not to beclassified as a failure.

7. Dimensions

7.1 Head and Body:7.1.1 The bolts shall conform to the dimensions for heavy

hex structural bolts specified in ANSI/ASME B18.2.6.7.1.2 The thread length shall not be changed except as

provided in Supplementary Requirement S1. Bolts with threadlengths other than those required by this specification shall beordered under Specification A 449.

7.2 Threads:

TABLE 2 Chemical Requirements for Type 3 Heavy Hex Structural Bolts A

Element

Composition, %

Type 3 BoltsA

A B C D E F

Carbon:Heat analysisProduct analysis

0.33–0.400.31–0.42

0.38–0.480.36–0.50

0.15–0.250.14–0.26

0.15–0.250.14–0.26

0.20–0.250.18–0.27

0.20–0.250.19–0.26

Manganese:Heat analysisProduct analysis

0.90–1.200.86–1.24

0.70–0.900.67–0.93

0.80–1.350.76–1.39

0.40–1.200.36–1.24

0.60–1.000.56–1.04

0.90–1.200.86–1.24

Phosphorus:Heat analysisProduct analysis

0.035 max0.040 max

0.06–0.120.06–0.125

0.035 max0.040 max

0.035 max0.040 max

0.035 max0.040 max

0.035 max0.040 max

Sulfur:Heat analysisProduct analysis

0.040 max0.045 max

0.040 max0.045 max

0.040 max0.045 max

0.040 max0.045 max

0.040 max0.045 max

0.040 max0.045 max

Silicon:Heat analysisProduct analysis

0.15–0.350.13–0.37

0.30–0.500.25–0.55

0.15–0.350.13–0.37

0.25–0.500.20–0.55

0.15–0.350.13–0.37

0.15–0.350.13–0.37

Copper:Heat analysisProduct analysis

0.25–0.450.22–0.48

0.20–0.400.17–0.43

0.20–0.500.17–0.53

0.30–0.500.27–0.53

0.30–0.600.27–0.63

0.20–0.400.17–0.43

Nickel:Heat analysisProduct analysis

0.25–0.450.22–0.48

0.50–0.800.47–0.83

0.25–0.500.22–0.53

0.50–0.800.47–0.83

0.30–0.600.27–0.63

0.20–0.400.17–0.43

Chromium:Heat analysisProduct analysis

0.45–0.650.42–0.68

0.50–0.750.47–0.83

0.30–0.500.27–0.53

0.50–1.000.45–1.05

0.60–0.900.55–0.95

0.45–0.650.42–0.68

Vanadium:Heat analysisProduct analysis

B

B

B

B0.020 min0.010 min

B

B

B

B

B

B

Molybdenum:Heat analysisProduct analysis

B

B0.06 max0.07 max

B

B0.10 max0.11 max

B

B

B

B

Titanium:Heat analysisProduct analysis

B

B

B

B

B

B0.05 max0.06 max

B

B

B

B

A A, B, C, D, E, and F are classes of material used for Type 3 bolts. Selection of a class shall be at the option of the bolt manufacturer.B These elements are not specified or required.

TABLE 3 Hardness Requirements for Bolts

Bolt Size, in.Bolt Length,

in.

Brinell Rockwell C

Min Max Min Max

1⁄2 to 1, incl Less than2D A

253 319 25 34

2D andover

. . . 319 . . . 34

11⁄8 to 11⁄2 ,incl

Less than3D A

223 286 19 30

3D andover

. . . 286 . . . 30

A Sizes 1.00 in. and smaller having a length shorter than 2D and sizes largerthan 1.00 in. having a length shorter than 3D are subject only to minimum andmaximum hardness.

D = Nominal diameter or thread size.

A 325 – 04

4

7.2.1 Uncoated—Threads shall be the Unified CoarseThread Series as specified in ANSI/ASME B1.1, and shall haveClass 2A tolerances.

7.2.2 Coated—Unless otherwise specified, zinc-coated boltsto be used with zinc-coated nuts or tapped holes that are tappedoversize, in accordance with Specification A 563, shall haveClass 2A threads before hot-dip or mechanically deposited zinccoating. After zinc coating, the maximum limits of pitch andmajor diameter shall not exceed the Class 2A limit by morethan the following amounts:

Nominal BoltDiameter (in.)

Oversize Limit, in.A

Hot-DipZinc

MechanicalZinc

1⁄2 0.018 0.0129⁄16 , 5⁄8 , 3⁄4 0.020 0.013

7⁄8 0.022 0.0151 to 11⁄4 0.024 0.01613⁄8 , 11⁄2 0.027 0.018

A Hot-dip zinc nuts are tapped oversize after coating, and mechanical zinc-coated nuts are tapped oversize before coating.

7.2.3 The gaging limit for bolts shall be verified duringmanufacture. In case of dispute, a calibrated thread ring gage ofthe same size as the oversize limit in 7.2.2 (Class X tolerance,gage tolerance plus) shall be used to verify compliance. Thegage shall assemble with hand effort following application oflight machine oil to prevent galling and damage to the gage.These inspections, when performed to resolve controversy,shall be conducted at the frequency specified in the qualityassurance provisions of ASME B18.2.6.

8. Workmanship

8.1 The allowable limits, inspection, and evaluation of thesurface discontinuities, quench cracks, forging cracks, headbursts, shear bursts, seams, folds, thread laps, voids, toolmarks, nicks, and gouges shall be in accordance with Specifi-cation F 788/F 788M (See Note 4).

NOTE 4—Specification F 788/F 788M nor F 1470 guarantee 100%freedom from head bursts. Sampling is designed to provide a 95%confidence level of freedom from head bursts in any test lot. Head bursts,within the limits in Specification F 788/F 788M, are unsightly but do notaffect mechanical properties or functional requirements of the bolt.

9. Number of Tests and Retests

9.1 Testing Responsibility:9.1.1 Each lot shall be tested by the manufacturer prior to

shipment in accordance with the lot identification controlquality assurance plan in 9.2 through 9.5.

9.1.2 When bolts are furnished by a source other than themanufacturer, the Responsible Party as defined in 14 shall beresponsible for assuring all tests have been performed and thebolts comply with the requirements of this specification (see4.5).

9.2 Purpose of Lot Inspection—The purpose of a lot inspec-tion program is to ensure that each lot conforms to therequirements of this specification. For such a plan to be fullyeffective it is essential that secondary processors, distributors,and purchasers maintain the identification and integrity of eachlot until the product is installed.

9.3 Lot Method—All bolts shall be processed in accordancewith a lot identification-control quality assurance plan. Themanufacturer, secondary processors, and distributors shallidentify and maintain the integrity of each production lot ofbolts from raw-material selection through all processing op-erations and treatments to final packing and shipment. Each lotshall be assigned its own lot-identification number, each lotshall be tested, and the inspection test reports for each lot shallbe retained.

9.4 Lot Definition—A lot shall be a quantity of uniquelyidentified heavy hex structural bolts of the same nominal sizeand length produced consecutively at the initial operation froma single mill heat of material and processed at one time, by thesame process, in the same manner so that statistical sampling isvalid. The identity of the lot and lot integrity shall bemaintained throughout all subsequent operations and packag-ing.

TABLE 4 Tensile Load Requirements for Full-Size Bolts

Bolt Size, Threads perInch, and Series

DesignationStress Area,A

in.2Tensile Load,B

min, lbf

Proof Load,B

LengthMeasure-

mentMethod

AlternativeProof

Load,B YieldStrengthMethod

Column 1 Column 2 Column 3 Column 4 Column 5

1⁄2 –13 UNC 0.142 17 050 12 050 13 0505⁄8 –11 UNC 0.226 27 100 19 200 20 8003⁄4 –10 UNC 0.334 40 100 28 400 30 7007⁄8 –9 UNC 0.462 55 450 39 250 42 500

1–8 UNC 0.606 72 700 51 500 55 75011⁄8 –7 UNC 0.763 80 100 56 450 61 80011⁄8 –8 UN 0.790 82 950 58 450 64 00011⁄4 –7 UNC 0.969 101 700 71 700 78 50011⁄4 –8 UN 1.000 105 000 74 000 81 000

13⁄8 –6 UNC 1.155 121 300 85 450 93 55013⁄8 –8 UN 1.233 129 500 91 250 99 87011⁄2 –6 UNC 1.405 147 500 104 000 113 80011⁄2 –8 UN 1.492 156 700 110 400 120 850

A The stress area is calculated as follows:

As 5 0.7854 [D 2 ~0.9743/n!#2

where:As = stress area, in.2,D = nominal bolt size, andn = threads per inch.

B Loads tabulated are based on the following:

Bolt Size, in. Column 3 Column 4 Column 5

1⁄2 to 1, incl11⁄8 to 11⁄2 , incl

120 000 psi105 000 psi

85 000 psi74 000 psi

92 000 psi81 000 psi

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5

9.5 Number of Tests—The minimum number of tests fromeach lot for the tests specified below shall be as follows:

Tests Number of Testsin Accordance With

Hardness, tensilestrength, proof load,and rotational capacity

Guide F 1470

Coating weight/thickness

The referenced coatingspecificationA

Surface discontinuities Specification F 788/F 788M

Dimensions andthread fit

ASME B18.2.6

A Guide F 1470 applies if the coating specification does not specify a testingfrequency.

10. Test Methods

10.1 Tensile, Proof Load, and Hardness:10.1.1 Tensile, proof load, and hardness tests shall be

conducted in accordance with Test Methods F 606.10.1.2 Tensile strength shall be determined using the Wedge

or Axial Tension Testing Method of Full Size Product Methodor the Machined Test Specimens Method depending on sizeand length as specified in 6.2.1-6.2.4. Fracture on full-size testsshall be in the body or threads of the bolt without a fracture atthe junction of the head and body.

10.1.3 Proof load shall be determined using Method 1,Length Measurement, or Method 2, Yield Strength, at theoption of the manufacturer.

10.2 Rotational Capacity—The zinc-coated bolt shall beplaced in a steel joint or tension measuring device andassembled with a zinc-coated washer and a zinc-coated andlubricated nut with which the bolt is intended to be used (seeNote 5). The nut shall have been provided with the lubricantdescribed in the last paragraph of the Manufacturing Processessection of Specification A 563. The joint shall be one or moreflat structural steel plates or fixture stack up with a totalthickness, including the washer, such that 3 to 5 full threads ofthe bolt are located between the bearing surfaces of the bolthead and nut. The hole in the joint shall have the same nominaldiameter as the hole in the washer. The initial tightening of thenut shall produce a load in the bolt not less than 10 % of the

specified proof load. After initial tightening, the nut positionshall be marked relative to the bolt, and the rotation shown inTable 6 shall be applied. During rotation, the bolt head shall berestrained from turning.

NOTE 5—Rotational capacity tests shall apply only to matched assem-bly lots that contain on A 325 bolt, one A 563 lubricated nut, and oneF 436 washer that have been zinc coated in accordance with eitherSpecifications A 153 or B 695. Both the bolt and nut components of thematched assembly shall be zinc coated using the same process.

11. Inspection

11.1 If the inspection described in 11.2 is required by thepurchaser, it shall be specified in the inquiry and contract ororder.

11.2 The purchaser’s representative shall have free entry toall parts of the manufacturer’s works, or supplier’s place ofbusiness, that concern the manufacture or supply of thematerial ordered. The manufacturer or supplier shall afford thepurchaser’s representative all reasonable facilities to satisfyhim that the material is being furnished in accordance with thisspecification. All tests and inspections required by the specifi-cation that are requested by the purchaser’s representative shallbe made before shipment, and shall be conducted as not tointerfere unnecessarily with the operation of the manufactur-er’s works or supplier’s place of business.

12. Rejection and Rehearing

12.1 Disposition of nonconforming bolts shall be in accor-dance with the Guide F 1470 section titled “Disposition ofNonconforming Lots.”

13. Certification

13.1 When specified on the purchase order, the manufac-turer or supplier, whichever is the responsible party as definedin Section 14, shall furnish the purchaser a test reports thatincludes the following:

13.1.1 Heat analysis, heat number, and a statement certify-ing that heats having the elements listed in 5.4 intentionallyadded were not used to produce the bolts,

13.1.2 Results of hardness, tensile, and proof load tests,13.1.3 Results of rotational capacity tests. This shall include

the test method used (solid plate or tension measuring device);and the statement “Nuts lubricated” for zinc-coated nuts whenshipped with zinc-coated bolts,

13.1.4 Zinc coating measured coating weight/thickness forcoated bolts,

13.1.5 Statement of compliance of visual inspection forsurface discontinuities (Section 8),

13.1.6 Statement of compliance with dimensional andthread fit requirements,

13.1.7 Lot number and purchase order number,13.1.8 Complete mailing address of responsible party, and

TABLE 5 Tensile Strength Requirements for Specimens Machined from Bolts

Bolt Diameter, in. Tensile Strength, min, psi (MPa) Yield Strength, min, psi (MPa) Elongation, in 4D, min, % Reduction of Area, min, %

1⁄2 to 1, incl. 120 000 (825) 92 000 (635) 14 35Over 1 to 11⁄2 105 000 (725) 81 000 (560) 1435

TABLE 6 Rotational Capacity Test for Zinc-Coated Bolts

Bolt Length, in.Nominal Nut Rotation, degrees

(turn)

Up to and including 4 3 dia 240 (2⁄3)Over 4 3 dia, but notexceeding 8 3 dia

360 (1)

Over 8 3 dia, but notexceeding 12 3 dia

420 (11⁄6)

Over 12 3 dia. Test not applicable

A 325 – 04

6

13.1.9 Title and signature of the individual assigned certi-fication responsibility by the company officers.

13.2 Failure to include all the required information on thetest report shall be cause for rejection.

14. Responsibility

14.1 The party responsible for the fastener shall be theorganization that supplies the fastener to the purchaser andcertifies that the fastener was manufactured, sampled, testedand inspected in accordance with this specification and meetsall of its requirements.

15. Product Marking

15.1 Manufacturer’s Identification— All Type 1 and 3 boltsshall be marked by the manufacturer with a unique identifier toidentify the manufacturer or private label distributor, as appro-priate.

15.2 Grade Identification:15.2.1 Type 1 bolts shall be marked “A 325.”15.2.2 Type 3 bolts shall be marked “A 325” with the

“A 325” underlined. The use of additional distinguishingmarks to indicate that the bolts are weathering steel shall be atthe manufacturer’s option.

15.3 Marking Location and Methods—All marking shall belocated on the top of the bolt head and shall be either raised ordepressed at the manufacturer’s option.

15.4 Acceptance Criteria—Bolts which are not marked inaccordance with these provisions shall be considered noncon-forming and subject to rejection.

15.5 Type and manufacturer’s or private label distributor’sidentification shall be separate and distinct. The two identifi-cations shall preferably be in different locations and, when onthe same level, shall be separated by at least two spaces.

16. Packaging and Package Marking16.1 Packaging:16.1.1 Unless otherwise specified, packaging shall be in

accordance with Practice D 3951.16.1.2 When zinc coated nuts are included on the same

order as zinc coated bolts, the bolts and nuts shall be shippedin the same container.

16.1.3 When special packaging requirements are required,they shall be defined at the time of the inquiry and order.

16.2 Package Marking:16.2.1 Each shipping unit shall include or be plainly marked

with the following information:16.2.1.1 ASTM designation and type,16.2.1.2 Size,16.2.1.3 Name and brand or trademark of the manufacturer,16.2.1.4 Number of pieces,16.2.1.5 Lot number; when nuts, washers or direct tension

indicators, or combination thereof, are ordered with A 325heavy hex structural bolts, the shipping unit shall be markedwith the lot number in addition to the marking required by theapplicable product specification,

16.2.1.6 Purchase order number, and16.2.1.7 Country of origin.

17. Keywords17.1 bolts; carbon steel; steel; structural; weathering steel

SUPPLEMENTARY REQUIREMENTS

The following supplementary requirements shall apply only when specified by the purchaser in thecontract or order. Details of these supplementary requirements shall be agreed upon in writing betweenthe manufacturer and purchaser. Supplementary requirements shall in no way negate any requirementof the specification itself.

S1. Bolts Threaded Full Length

S1.1 Bolts with nominal lengths equal to or shorter thanfour times the nominal bolt diameter shall be threaded fulllength. Bolts need not have a shoulder, and the distance fromthe underhead bearing surface to the first complete (full form)thread, as measured with a GO thread ring gage, assembled by

hand as far as the thread will permit, shall not exceed the lengthof 21⁄2 threads for bolt sizes 1 in. and smaller, and 31⁄2 threadsfor bolt sizes larger than 1 in.

S1.2 Bolts shall be marked in accordance with Section 15,except that the symbol shall be “A 325 T” instead of “A 325.”

A 325 – 04

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SUMMARY OF CHANGES

Committee F16 has identified the location of selected changes to this standard since the last issue, A 325–02,that may impact the use of this standard. (Approved Jan. 1, 2004.)

(1) Revised Certification Section 13.1.5 to require statement ofcompliance of visual inspection for all surface discontinuities.

Committee F16 has identified the location of selected changes to this standard since the last issue, A 325–01, that may impactthe use of this standard. (Approved Jan. 10, 2002.)

(1) In 1.4 limited specification to heavy hex structural boltsonly.(2) In 4.1 revised to require that Type 3 bolts be quenched inoil.(3) In 4.5.1 revised to require retesting only for propertiesaffected by the secondary processing.(4) In 4.5.2 rephrased to preclude the implication that blackbolts require rotational capacity testing.(5) In Table 2, reduced the phosphorus limits for compositionsA, D, E, and F and the sulfur limits for compositions A, B, andD.(6) In 6.2.1 revised the minimum length for full-size wedgetesting.(7) In 6.2.3 provided for full-size axially tension testing boltsshorter than 21⁄4 D down to 2D. Also added requirements forqualifying short bolts on the basis of hardness.(8) In Table 3, Hardness, changed 3D to 2D for sizes 1.00 in.and smaller(9) Added Table 5 specifying tensile, elongation, and reduc-tion in area requirements for machined specimens.(10) In 7.1.1 deleted all wording that permitted the purchaserto specify dimensions other than “heavy hex structural.”

(11) In 7.1.1 changed the dimensional reference from B18.2.1to B18.2.6.(12) 7.2.2 revised to specify maximum pitch and majordiameter limits for mechanically coated bolts.(13) Deleted Table 7 (formerly Table 6), “Sample Size forInspection of Hot-Dip or Mechanically Deposited Zinc-CoatedThreads” and referenced ASME B18.2.6, which includesreferences for testing frequency.(14) Deleted former section 9, “Head Bursts,” and includedthe requirements by reference to Specification F 788/F 788Min 8.1.(15) In 9.3 and 9.4 changed “Production Lot” to “Lot” andredefined “Lot.”(16) 9.5, “Number of Tests,” revised to invoke SpecificationF 1470 for hardness, tensile, proof load, and rotational capacitytests. Coating weight/thickness and surface discontinuitiessampling referenced to the applicable spec. Dimensional andthread compliance sampling referenced to ASME B18.2.6.(17) Section 12, “Rejection and Rehearing,” revised to invokeF 1470.(18) In 15.2.1 deleted option permitting marking with threeradial lines 120° apart.

ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.

This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.

This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website(www.astm.org).

A 325 – 04

8

Designation: A 325M – 04

METRIC

An American National Standard

Standard Specification forStructural Bolts, Steel, Heat Treated 830 MPa MinimumTensile Strength [Metric] 1

This standard is issued under the fixed designation A 325M; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.

This standard has been approved for use by agencies of the Department of Defense.

1. Scope*

1.1 This specification2 covers two types of quenched andtempered, steel, metric heavy hex structural bolts having aminimum tensile strength of 830 MPa (Note 1).

1.2 The bolts are intended for use in structural connections.These connections are comparable to those covered under therequirements of the Specification for Structural Joints usingASTM A 325 or A 490 bolts, approved by the ResearchCouncil on Structural Connections; endorsed by the AmericanInstitute of Steel Construction and by the Industrial FastenerInstitute.3

1.3 The bolts are furnished in sizes M12 to M136 inclusive.They are designated by type denoting chemical composition asfollows:

1.3.1 Type 1—Medium-carbon, carbon boron, medium car-bon alloy, or alloy boron steel.

1.3.2 Type 2—Withdrawn in 2003.1.3.3 Type 3—Weathering Steel.1.4 This specification is applicable to metric heavy hex,

structural bolts only.1.5 Terms used in this specification are defined in Specifi-

cation F 1789.1.6 The following safety hazards caveat pertains only to the

test methods portion, Section 10, of this specification.Thisstandard does not purport to address all of the safety concerns,if any, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory require-ments prior to use.

NOTE 1—This specification is the metric companion to the inch poundSpecification A 325.

2. Referenced Documents

2.1 ASTM Standards:4

A 153 Specification for Zinc Coating (Hot Dip) on Iron andSteel Hardware

A 490M Specification for High-Strength Steel Bolts,Classes 10.9 and 10.9.3, for Structural Steel Joints [Metric]

A 563M Specification for Carbon and Alloy Steel Nuts[Metric]

A 751 Test Methods, Practices, and Terminology forChemical Analysis of Steel Products

B 695 Specification of Coatings of Zinc Mechanically De-posited on Iron and Steel

D 3951 Practice for Commercial PackagingF 436M Specification for Hardened Steel Washers [Metric]F 606M Test Methods for Determining the Mechanical

Properties of Externally and Internally Threaded Fasteners,Washers, and Rivets [Metric]

F 788/F 788M Specification for Surface Discontinuities ofBolts, Screws, and Studs, Inch and Metric Series

F 959M Specification for Compressible Washer-Type Di-rect Tension Indicators for Use with Structural Fasteners[Metric]

F 1470 Guide for Fastener Sampling for Specified Mechani-cal Properties and Performance Inspection

F 1789 Terminology for F16 Mechanical FastenersG 101 Guide for Estimating the Atmospheric Corrosion

Resistance of Low-Alloy Steels2.2 ASME Standards:B 1.13M Metric Screw Threads51 This specification is under the jurisdiction of ASTM Committee F16 on

Fasteners and is the direct responsibility of Subcommittee F16.02 on Steel Bolts,Nuts, Rivets, and Washers.

Current edition approved Jan. 1, 2004. Published January 2004. Originallyapproved in 1979. Last previous edition approved in 2003 as A 325M – 03.

2 For ASME Boiler and Pressure Vessel Codeapplications, see related Specifi-cation SA-325M in Section II of that Code.

3 Available from American Institute of Steel Construction (AISC), One E.Wacker Dr., Suite 3100, Chicago, IL 60601-2001.

4 For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at service@astm.org. ForAnnual Book of ASTMStandardsvolume information, refer to the standard’s Document Summary page onthe ASTM website.

5 Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave., New York, NY 10016-5990.

1

*A Summary of Changes section appears at the end of this standard.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.

B 18.2.3.7M Metric Heavy Hex Structural Bolts5

B 18.18.3M Inspection and Quality Assurance for SpecialPurpose Fasteners5

B 18.24.1 Part Identifying Number (PIN) Code System5

3. Ordering Information

3.1 Orders for heavy hex structural bolts under this speci-fication shall include the following:

3.1.1 Quantity (number of pieces of bolts and accessories).3.1.2 Size, including nominal bolt diameter, thread pitch

and bolt length.3.1.3 Name of product, heavy hex structural bolts.3.1.4 When bolts threaded full length are required, Supple-

mentary Requirement S1 shall be specified.3.1.5 Type of bolt; Type 1 or Type 3. When the type is not

specified, either Type 1 or Type 3 shall be furnished at thesupplier’s option.

3.1.6 ASTM designation and year of issue.3.1.7 Other components such as nuts, washers, and com-

pressible washer-type direct-tension indicators, if required.3.1.8 Zinc Coating—Specify the zinc-coating process re-

quired, for example, hot-dip, mechanically deposited, or nopreference (see 4.3).

3.1.9 Other Finishes—Specify other protective finish, ifrequired.

3.1.10 Test reports, if required (see Section 13).3.1.11 Supplementary or special requirements, if required.3.1.12 For establishment of a part identifying system, see

ASME B18.24.1.

NOTE 2—A typical ordering description follows: 1000 pieces,M24333100, heavy hex structural bolts, Type 1 ASTM A 325M - 03,each with one hardened washer and one heavy hex nut, mechanicallydeposited zinc coating (see 3.1.8 for any special requirements).

3.2 Recommended Nuts:3.2.1 Nuts conforming to the requirements of Specification

A 563M are the recommended nuts for use with A 325Mmetric heavy hex structural bolts. The nuts shall be of the classand have a surface finish for each type of bolt as follows:

Bolt Type and Finish Nut Class and Finish Specification1, plain (noncoated) A 563M—8S or 8S3, plain1, zinc-coated A 563M—10S, zinc-coated3, plain A 563M—8S3, plain

3.3 Recommended Washers:3.3.1 Washers conforming to Specification F 436M are the

recommended washers for use with Specification A 325MMetric heavy hex structural bolts. The washers shall have asurface finish for each type of bolt as follows:

Bolt Type and Finish Washer Finish1, plain (uncoated) plain (uncoated)1, zinc-coated zinc-coated3, plain weathering steel, plain

3.4 Other Accessories:3.4.1 When compressible washer type direct tension indica-

tors are specified to be used with these bolts, they shallconform to the requirements in Specification F 959M Type 8.8.

4. Materials and Manufacture

4.1 Heat Treatment:

4.1.1 Type 1 bolts produced from medium carbon steel shallbe quenched in a liquid medium from the austenitizingtemperature.

4.1.2 Type 1 bolts produced from carbon steel to whichchromium, nickel, molybdenum, or boron were intentionallyadded shall be quenched only in oil from the austenitizingtemperature.

4.1.3 Type 3 bolts shall be quenched only in oil from theaustenitizing temperature.

4.1.4 Type 1 bolts, regardless of the steel used, and Type 3bolts, shall be tempered by reheating to not less than 427°C.

4.2 Threading—Threads shall be cut or rolled.4.3 Zinc Coatings, Hot-dip and Mechanically Deposited:4.3.1 When zinc-coated fasteners are required, the pur-

chaser shall specify the zinc coating process, for example, hotdip, mechanically deposited, or no preference.

TABLE 1 Chemical Requirements for Type 1 Bolts

ElementCarbon Steel

HeatAnalysis

ProductAnalysis

Carbon 0.30–0.52 0.28–0.55Manganese, min 0.60 0.57Phosphorus, max 0.040 0.048Sulfur, max 0.050 0.058Silicon 0.15–0.30 0.13–0.32

ElementCarbon Boron Steel

HeatAnalysis

ProductAnalysis

Carbon 0.30–0.52 0.28–0.55Manganese, min 0.60 0.57Phosphorus, max 0.040 0.048Sulfur, max 0.050 0.058Silicon 0.10–0.30 0.08–0.32Boron 0.0005–0.003 0.0005–0.003

ElementAlloy Steel

HeatAnalysis

ProductAnalysis

Carbon 0.30–0.52 0.28–0.55Manganese, min 0.60 0.57Phosphorus, max 0.035 0.040Sulfur, max 0.040 0.045Silicon 0.15–0.35 0.13–0.37Alloying Elements A A

Alloy Boron Steel

HeatAnalysis

ProductAnalysis

Carbon 0.30–0.52 0.28–0.55Manganese, min 0.60 0.57Phosphorus, max 0.035 0.040Sulfur, max 0.040 0.045Silicon 0.15–0.35 0.13–0.37Boron 0.0005–0.003 0.0005–0.003Alloying Elements A A

A Steel, as defined by the American Iron and Steel Institute, shall be consideredto be alloy when the maximum of the range given for the content of alloyingelements exceeds one or more of the following limits: Manganese, 1.65 %; silicon,0.60 %; copper, 0.60 % or in which a definite range or a definite minimum quantityof any of the following elements is specified or required within the limits of therecognized field of constructional alloy steels: aluminum, chromium up to 3.99 %,cobalt, columbium, molybdenum, nickel, titanium, tungsten, vanadium, zirconium,or any other alloying elements added to obtain a desired alloying effect.

A 325M – 04

2

4.3.2 When hot-dip is specified, the fasteners shall bezinc-coated by the hot-dip