Rebar Grades [Top]

Our products are made in accordance with Philippine National Standards for Steel Bars for

Concrete Reinforcement, under PNS-49:2002.

Spec i f icat ions and Grad ing [Top]

The three grades under this specification – namely, Grades PNS 230, 275, and 415 –trace

their roots to ASTM specifications. And the terms ‘Structural’, ‘Intermediate’, and ‘High-

tensile’ originated from earlier versions of ASTM-A615 but remained unchanged in deference

to custom and familiarity among users. The table below provides a handy reference as to the common understanding in the market regarding these grades.

ASTM vs PNS Codes Popular Nomenclature Typical Application

Grade 33 / PNS 230 Structural Grade Low-rise Buildings and Low Loading Conditions

Grade 40 / PNS 275 Intermediate Grade Medium-rise Structures / Infrastructure Work

Grade 60 / PNS 415 High-Tensile Grade Medium & High-rise Structures / Infrastructure

The three grades are distinguished by the different color markings painted at the ends of

each bar, as shown in the following table:

Weldab i l i ty o f a Rebar [Top]

It must be noted that, in the current PNS 49, rebars are further categorized into ‘weldable’

and ‘non-weldable’ grades. The difference between the two categories is primarily rooted in

their different chemical compositions and carbon equivalents (CEQ). Despite the different

nomenclatures and their connotations, both ‘Weldable’ and ‘Non-weldable’ grades can

actually be welded. However, the relatively lower carbon content and CEQ of the so-called

‘weldable’ grade does make it easier to weld without having to worry about pre-heating and

post-heating requirements and procedures, that is a concern highlighted especially in temperate situations.

Rebar S izes [Top]

The standard sizes that the Company manufactures and sells are as follows: 10mm, 12mm,

16mm, 20mm, 25mm, 28mm, 32mm, and 36mm. For special orders, it can also make 40mm and 50mm bars.

The Nominal S ize o f a Rebar [Top]

For both the plain round bar and the rebar, the word ‘size’ and nominal diameter are used

interchangeably.

For a rebar, alternatively known as a ‘deformed steel bar’, its ‘size’ specifically refers to the

size of a plain round bar having the same weight per meter as the rebar.

A specific ‘size’ of plain round bar refers to its nominal diameter. This ‘size’ also refers to the diameter of a circular plain round bar having a certain unit mass or weight per meter.

A plain round bar and a rebar of the same ‘size’ will have the same unit mass or weight per meter of bar.

The Proper Way o f Measur ing a P la in Round Bar [Top]

For a plain round bar, determining its 'size' involves simply taking a direct physical

measurement of its diameter since its circular cross section should remain quite uniform

throughout its length. A plain round bar is considered to be dimensionally acceptable if its diameter, as measured, falls within the dimensional tolerances allowed by the Standard.

The Proper Way o f Measur ing a Rebar [Top]

A rebar however is not measured in the same way as a plain round bar. Because of its non-

uniform cross section, a rebar must comply with the allowable ‘Variation in Mass’ (VIM) in

lieu of measurement of its diameter. Checking for this VIM involves taking and weighing one meter of rebar and comparing the findings against the standard value.

Weight To lerance [Top]

Because variation in cross sectional area occurs during hot rolling, a corresponding variation

in linear weight is to be expected. For this reason, PNS-49 provides for an allowable

‘variation in mass’ (VIM) of ±6%, measured using one meter of rebar.

Length To lerance [Top]

The cut length of a rebar varies as well because of shrinkage as it cools down. The standard

however limits this shrinkage, and the minimum lengths of the finished rebar are shown below.

Std. Length (m) Min. Acceptable Length (m)

6.0 5.960

7.5 7.453

9.0 8.935

10.5 10.440

12.0 11.940

Our rebar comes in these commercial lengths: 6.0, 7.5, 9.0, 10.5, and 12.0 meters. Special

lengths of 13.5 and 15.0 meters are subject to special orders and negotiations.

Mechanica l Property Spec i f icat ions [Top]

MECHANICAL PROPERTIES

Class Grade

Yield

Strength,

MPa min.

Tensile

Strength,

MPa min.

Specimen

Elongation

in 200mm,

% min.

Bending

Angle

Diameter of

Pin (d =

nominal

diameter of

specimen)

Hot-Rolled

Non-Weldable Deformed Steel Bar

230 230 390 D<25mm

D≥25mm

18

16 180

3d

4d

275 275 480 D<25mm D≥25mm

10 8

180 4d 5d

415 415 620 D<25mm D≥25mm

8 7

180 5d 6d

Hot-Rolled

Weldable Deformed

Bar

230 230 390 D<25mm D≥25mm

20 18

180 3d 4d

275 275 480 D<25mm D≥25mm

16 14

180 4d 5d

415 415* 550** D<25mm

D≥25mm

14

12 180

5d

6d

* Maximum yield strength of Weldable steel bars shall not exceed 540 MPa

** Tensile strength shall not be less than 1.25 times the actual yield strength

Surface Deformat ions Spec i f icat ions [Top]

DEFORMATION REQUIREMENTS

Nominal

Diameter

Max. Average Spacing

of Lugs

Height Tolerance of

Lugs Max. Summation of Gaps

(mm)

Minimum Maximum

10 7.0 0.4 0.8 7.8

12 8.4 0.5 1.0 9.4

16 11.2 0.7 1.4 12.6

20 14.0 1.0 2.0 15.7

25 17.5 1.2 2.4 19.6

28 19.6 1.4 2.8 22.0

32 22.4 1.6 3.2 25.1

36 25.2 1.8 3.6 27.5

Tab le of S tandard Weights [Top]

STANDARD WEIGHT OF DEFORMED ROUND STEEL BARS

Bar Diameter ∅mm

Unit Weight

Kg/m

Bar Commercial Length

6.0 m 7.5 m 9.0 m 10.5 m 12.0 m

10 0.616 3.696 4.620 5.544 6.468 7.392

12 0.888 5.328 6.660 7.992 9.324 10.656

16 1.578 9.468 11.835 14.202 16.569 18.936

20 2.466 14.796 18.495 22.194 25.893 29.592

25 3.853 23.118 28.898 34.677 40.457 46.236

28 4.834 29.004 36.255 43.506 50.757 58.008

32 6.313 37.878 47.348 56.817 66.287 75.756

36 7.990 47.940 59.925 71.910 83.895 95.880