Iowa State University

From the SelectedWorks of Frank E. Peters

1996

Assessing Dimensional Repeatability ofMetalcasting ProcessesFrank E. Peters, The Pennsylvania State UniversityR. Velaga, The Pennsylvania State UniversityR.C. Voigt, The Pennsylvania State University

Available at: https://works.bepress.com/frank_peters/16/

Assessing Dimensional Repeatability of Metalcasting Processes

AFS Research

F.E. Peters R. Velaga R.C. Voigt Pennsylvania State University University Park, Pennsylvani a

ABSTRACT

Rob11st techniq11es to assess the dimensional capabilities of production meta/castings have been developed and are de­scribed. Initial consideration must be given to the meas11rement techniques and methodologies 11sed to ensure that measurement sntem errors are not a significant part of dimensional variabil­it\ s111dies. The use of Gage R & R techniq11es for meas11rement system analysis are described. Proced11resfor selecting castings and casting geometries to be included in dimensional studies are also described, as well as casting and feature descriptors that aid in subsequent data analysis.

The influence of feature length, casting weight and parting line considerations 011 dimensional repeatability are described for iron castings made in green sand molds. The dimensional m riability observed is compared to c11rrent dimensional toler­ance stall{/ards. This ongoing research is part of the American Meta/casting Consortia (A MC) research effort, supported by the U.S. Def e11se Logistics Agency.

INTRODUCTION

The increasing demand fo r closer dimensional tolerances places continuing demand on metalcasters to control casting geometry. lronically, lhe reverse engineering used by most foundries to satisfy customer's dimensional conformance requirements can be thought of as "the dimensions controlling the foundry" rather than "lhe foundry controll ing the dimensions."

Dimensional control practices are based on anecdotal informa­tion, "rules of thumb" and dimensional data from inadequate mea­surement systems, rather than on statistically sound information. A lack of sound dimensional control practices has limited the industry's market share for near-net-shape components. In addition , inadequate pattern shrinkage allowances and traditional trial-and-error pattern correction methods add unnecessary cost and lead time to lhe initial casting approval process.

This tremendous dimensional challenge for the metalca ting industry has been the motivation for lhe current comprehensive effort to re-examine dimensional variability and dimensional control of castings.

Comprehensive research on the dimensional capabilities of foundry processes for important foundry segments is ongoing . The primary effort is to conduct dimensional capability assessments of production

casting processes for a broad spectrum of casting alloys, molding processes and casting size ranges.

The goals of this effort are to:

dete rmine the influence of casting design and foundry pro­cessing variables on the di mensional variability of casting features;

• develop customer dimensional tolerance specifications that re flect the true dimensional capabi lities of casting industry segments;

• develop improved pattern shrinkage allowance guidelines: promulgate dimen ional control strategies that can be effec­tively used by foundries to produce close-tolerance castings.

T he most comprehensive standard for dimensional tolerances of metalcasting features is International Standards Organization (TSO) 8062 standard. 1 This standard includes 16 different dimensional tolerance grades for specific mold types and alloys. The allowable casting tolerance for a given feature is dependent only on the size of the feature.

Dimensional tolerance guidelines also exist for certain industry segments. These include: Steel Founders' Society of America toler­ances for steel castings ( 1980),2 The North American Die Casting Association published standards fordiecastings ( 1994),3 Investment Casting Institute published tolerances for investment castings ( 1993),4

and Aluminum Association publi hed standards for aluminum per­manent mold castings ( 1988).5

Many large users of castings have also developed proprietary dimensional tolerance guidel ines for their internal use. Figure 1 shows the relationship between the published ISO 8062 tolerance specifications for iron castings and the dimensional guidelines from live diffe rent users of iron castings. 1 From this comparison, it is evident that the tolerance guidelines from all five different users of iron castings are tighter than the CT 12 specificat ions and, in most cases, are tighter than the CT I 0 speci fications for feature lengths less than 500 mm. This possibly indicates that the iron casting industry's ability to control dimensions are better lhan is indicated by the published standards .

Geometric dimensioning and tolerancing techniques are also becoming more widely used by designers to communicate the func tional needs of components. ISO has published a draft standard, ISO 8062-2, Castings-System of Geometrical Tolerances, which will be the first comprehensive geometric tolerance specifications fo r castings.6 Limited geometrical design and tolerance information also exists for investment castings and diecastings.2.3

These feature and geometric specifications, typically based on feature length, are important tools to communicate the industry's dimensional capabilities to customers. However, many other casting geometry characteristics and foundry process control factors can be expected to influence dimensional repeatability. Careful study of casting dimensional variabi lity, and the sources of variation, can lead to improvements in dimensional performance.

In this paper, foundry variables that contribute to casting dimen­sional errors are identified and illustrated in lishbone diagrams. Robust techniques that can be used by the foundry to assess the dimensional capabilities of production metalcastings are described. Both casting selection and inspection strategie will be described to accurate ly assess dimensional capabilities. Also described is the use of gage repeatability and reproducibility (Gage R & R) techniques to assess measurement system variabili ty. Examples of dimensional variabi lity studies and data analysis from ducti le and gray iron foundries are described.

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12

ISO CT12 10

e ti 0 ;

8

~ ti

r-l 0 E-4 6 ti ~ ::I +J ., ti It. ' r-l ., +J 0

E-4 2

0 100 200 300 400 500 600 700 800 900 1000

Feature Length (mm)

Fig. 1. Comparison between ISO 8062 dimensional tolerance specification for iron castings and various proprietary dimensional tolerance specifications from casting buyers.

Molding Methods

Molding Materials

Molding Equipment

Geometry

Fig. 2. Fishbone diagram illustrating the five major categories of variables that affect dimensional variability.

Number of Castings per Mold Mold

Compaction Method ---."'<'0--- Flask Type

Use of Jackets

Dimensional -------.,,----~---~ Variabilit~

Core Wash

Corebox Filling Method

Core Making

Fig. 3. Expanded fishbone diagram illustrating the molding method variables that affect dimensional variability.

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Patterns

Pattern Set Up _ ___,_...

Al ignment

Core Boxes

Pattern Material

""'--- Condition

Fig. 4. Expanded fishbone diagram illustrating the molding equipment variables that affect dimensional variability.

Alloy Type Heat Treatment

~ ~ ~ c: .g ·I Dimensional I '6 ., Variabilit} c:

/ 0 u .... u ~

Pouring 1 emperaturc

Fig. 5. Expanded fishbone diagram illustrating the metal condition variables that affect dimensional variability.

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•~' ----------------------------------~?It--

FACTORS INFLUENCING DIMENSIONAL VARIABILITY

When dbcussing dimensional e rrors or non-conformity, it is impor­tant to distinguish between dimensional accuracy and dimensional \ ariability. Lack of dimensional accuracy-an indication of how close the casting dimension is to the actual target value-is o ften refe rred to as a systematic erro r. The main causes for poor dimen­sional accuracy are patte rn equipment erro rs. pattern wear and casting contraction uncertainty. much of which can be corrected before production runs. Lack of dimensional consistency-the varia­tion of individual casting dimensions about the mean casting dimen­-.1on- is often referred to as random error.

Many foundry process variables contribute LO the dimensional inconsistency of castings. It is, therefore, important that s ignificant sources of dimensional variability be identified, and that appropriate proce~s controh be established to minimize them. The fishbone diagram of Fig. 2 describes major factors influencing casting dimen­sional 'ariability for sand castings processes. These major factors can be further expanded to indicate individual variable that can affect dimen<,ional variability, as shown in Figs. 3-7.

Molding Sand

Core rype(sJ

Binder

Level

Fig. 6. Expanded fishbone diagram illustrating the molding variables that affect dimensional variability.

Overall Casting Geomc1ry

Pro1ec1cd Arca of

Casting on Paning Lone

Volume of Internal Coring

Rclauon of r caturc to Mold Wall and Cores

Feature Geometry

Pour Weight

Orientation of F eaturc Relative to Parting Line

Fig. 7. Expanded fishbone diagram illustrating the geometry \'ariables that affect dimensional variability.

AFS Transactions

ESTABLISHING DIMENSIONAL CAPABILITY STUDIES

In the fo llowing sections, a framework for developing and conduct­ing in-hou!>e casting and tooling dimensional control programs are described. These same procedures are being used in dimensional studies across the country. Robust casting and pattern inspection procedures are detailed. including guide lines for the selection of castings, selection of casting features, and the collection of casting and pattern feature measurements. Casting inspection efforts must be preceded by a complete analysis of the foundry mea urement sys­tems to be used, to ensure their adequacy. Measurement system analysis to determine the adequacy of a measurement system for casting inspection is the starting point for any study of casting dimensional variability. The measurement system is made up of all the equipment, fixtures and operato rs used to make a measurement.

Measurement System Analysis

The suitability of a measurement system for a particular measure­ment can be assessed by conducting simple Gage R & R tests. The measurement system analysis quantifies the mea urement error components of repeatabi lity (i.e., the ability to generate the same measurement, using the same equipment) and reproducibility (i.e., how well two inspectors can measure the same feature). The Gage R & R can then be compared to eitherthe part variabi lity being assessed or to the customer's dimensional tolerance to determine system acceptability.

If the casting feature measurements are being used to verify whether the castings meet c ustomer tolerance, then the Gage R & R should be compared as a percentage of the customer tolerance. On tbe other hand, if the measurements are being taken to determine the foundry's dimensional capabilities or for process contro l, then Gage R & R should be compared to the actual part variability. The Automoti ve Industry Action Group provides detailed instructions to determine the adequacy of most measurement systems. The fo llow­ing summarizes the AIAG acceptance standards for characterizing measurement variability:?

% Gage R& R less that I 0% 10--30 %

Acceptability preferred acceptable

greater than 30% unacceptable

This acceptance criterion, based on the marginal acceptance range spec ified by AJAG, will ensure that the dimensional variability included in a casting study will not be confounded by measurement system variability.7 In addition , the smallest measurement increment must be, at most, 1/ 10 of the variability Lo be measured.

Many pieces of inspection equipment commonly used in found­ries have been found to be inadequate. Large repeatability e rro rs are ofte n caused by the use of inadequate equi pment, improper use of measurement instruments, improper location on drafted surfaces or insufficient fixturing. Large reproducibility errors, on the other hand, can be attributed to the difference in the measurement techniques adopted by different operators.

Because the inspection equipment and systems used from cast­ing-to-casting and feature-to-feature vary significantly, it is neces­sary to measure Gage R & R for the measurement system under con ideration. rather than assume adequacy. When evaluating the Gage R & R for a coordinate measuring machine or layout machine, it is important that the part be refixtured before each measurement, since setup constitutes a part of the overall measurement system. Appendix A summarizes appropriate Gage R & R test methods for casting feature inspection. Complete details are described in the AJAG guidelines.7

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Selection of Castings and Features

Castings selected for dimensional capabi lity studies should represent the range of foundry process variables and casting type and size ranges at a given foundry site. Alternatively, the dimensional capa­bility assessment can also be tailored to study any specific aspect of production parts that is of critical importance to the foundry. How­ever, only castings from typical production runs should be assessed. "Special" casting runs produced for dimensional studies invariably do not renect true production dimension capabilities.

From each casting selected, specific features hou Id be chosen for study, so as to represent common casting geometries and molding configurations. Ease of measurement on the features selected for a capabili ty study should be considered to ensure that measurement variability is appropriately small. Care should be taken that the selected features capture the important dimensional information needed. Appendix B is a survey form that can be used to identify a variety of feature types and to describe and record the associated feature characteristics and molding variables that innuence dimen­sional repeatability.

Once the tentative casting features are chosen, the measurement systems must be selected and evaluated for acceptability. If similar measurement techniques and the same operators are used for other similar feature types, measurement system analyses do not have to be repeated. If Gage R & R is acceptable, the specific measurement procedures detailing the instrument type, measurement technique and exact measurement location for each measured casting feature should be documented to ensure measurement consistency through­out a dimensional study.

To obtain a true picture of the dimensional capability and to assess dimensional variability from a customer's perspective, it is neces­sary to capture the dimensional variability of casting features, over a period of time, from multiple production runs. A sample size of about thirty castings from at least two different batches can be used to assess process capabilities. If possible, the runs should be collected as far apart as feasible. By doing so, the e ffects of foundry variables, such as operator and molding machine differences from one run to another, wi ll be captured. Furthermore, samples measured over a larger time frame may capture dimen ional variability caused by other factors , such as ambient temperature, long term sand system changes or nask pin wear.

Pattern Equipment Measurement

To betler predict the shrinkage a llowance for casting features, it is very desirable to also measure corresponding patterns and corebox dimensions as a part of casting dimensional variability studies. Both process variables and casting geometry can be expected to innuence the shrinkage allowance for casting dimensions. If different mea­surement techniques from those used to measure casting features are used to measure the pattern features, then the measurement syste m analysis procedures must be repeated to ensure that they are adequate for pattern feature inspection. Pattern measurements that are not accessible, such as dimensions across the pattern plate, must be omitted un less it can be demonstrated that these dimensions can be mathe matically constructed.

184

Data Analysis

All casting and pattern data, along with all the accompanying features and process descriptors, make up the dimensional vanabilit) database. The first step in the data analysis is to find the mean dimension and the standard deviation of the sample lot for each casting feature measured. The sample mean, which is a measure of the central tendency, can be compared to the corre ponding drawing and pattern dimension to check for conformance of dimensions and shrinkage allowance, respectively. Any non-conformance can be viewed as a possible need for pattern adj ustment or reevaluation of the shrinkage allowance used for future patterns.

The standard deviation, which is a measureofthedatadispers1on. indicates conformance or non-conformance to a specified dimen­sional tolerance. In a normally distributed data, 99.73% of the data lie within ±3 standard deviations of the mean. Thus. a process\\. Ith the mean centered on the specified drawing dimension and total specified tolerance greater than six times the standard de\1auon would result in less than I% dimensional scrap for a feature with no pattern errors. An unacceptable percentage of non-conformance would require allention in the areas of process improvement to reduce dimensional variability.

Such dimensional capability information can be used by found­ries in several ways. Analysis can be performed to identif) and iso late variables that cause significant dimensional variability. Iden­tifying such causes can help initiate counter-measures to reduce dimensional variations. Knowledge of the process limitations and capabilities can be used as a powerful tool to evaluate new jobs and to establi sh to lerance guidelines. In short, accurate dimensional knowledge can be used to sell dimensions and exploit the inherent near-net-shape capabi lities of the metalcasting process.

Data Analysis Example

Dimensional Capabilities of Iron Castings The following data was collected as a part of ongoing research at Penn State University. The data is presented, here, only to demon­strate the use of the data col lecLion principles and of the accompany­ing database, to determine a foundry 's dimensional capability. This data may no t be representative of the industry, in general.

Figure 8 illustrates the size and weight distribucion of casting~ measured from two different foundries, during the initial phase. of this project. Included in these plots are both gray and ductile iron castings made in green sand molds for various molding sy terns. Casting features as long as 280 mm and casting weights up to 29 kg were evaluated.

Figure 9 illustrates casting feature dimension variability as a function of feature length for various casting made in various green sand molds. (In this and all subsequent figures, the dimension variability is expressed in terms of the ''total tolerance," or six standard deviations (6cr), about the mean. Each data point shown m these figures is the calculated six-standard-deviation value, deter­mined from measurements of the same casting feature in 30 cast­ings.)

It is evident from the figure that the feature dimension variabilit> increases as feature length increases for all molding processe .

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25 a c

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x High Pressure Verticle Parting Line

c o High Pressure Honzon1al Parting Line

c Manual Jolt Squeeze

c ID

x

0

c c

c x

0 so 100 150 200 250 300

Feature Length (mm)

Fig. 8. Feature length and casting weight distribution of casting features measured as part of dimensional variability studies.

5

x High Pressure Verticle Parting Line

o High Pressure Horizontal Parting Line o _p Manual Jolt Squeeze

4

c 0

e .§. 8 0 ~ 3 2i • o ;:: a c • > 0 !! c " c a c ... .. x 0 ...

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0 o x '*.O ~ XO \ ~

o x 0 x x x xx x 0 x 0 x

x o 0 0 Xx x 0

0 50 100 150 200 250 300

Feature Length (mm)

Fig. 9. Influence of feature length on dimensional variability for various green sand molding methods.

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a I x High Pressure Verticle Parting~ o High Pressure Honzontal Parting Line

4 a Manual Jolt Squeeze

a a E .§. 8 ~

0 3

:ii a a .! :a a a a > a

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' ~g 0 0

e x ~! a

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0 5 10 15 20 25 30

Casting Weight (kgs)

Fig. 10. Influence of casting weight on dimensional variability for various green sand molding methods.

20

18

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l• Grey Iron 1 16

!• Ductile Iron /

14

• • u ll 12 • M :s u u 0 10 ~ 0

M • 8

1 6

4

2

0

-1 0% - 9% -8% -7% - 6% -5% - 4% -3% -2 % -1% 0% 1% 2% 5% 6%

Percent Shrinkage

Fig. 11. Histogram of observed casting shrinkage values for ductile and gray iron production castings.

186 AFS Transactions

The influence of molding equipment type on dimensional variability is also evident. It is ob erved that dimensional variability is less for green sand castings made from high-pressure molding processes 1han it is for manual squeeze-jolt molding processes. Much of the scatter in 1he data is due to the influence of other variables that co111ribute to dimensional variabi lity.

Figure 10 shows the e ffects of casting weight on the casting feature dimension variability. Feature variability also increases as the overall casting weight increases That is, a feature of the same length can be expec1ed 10 exhibit more variabilily on a heavier casling. This suggesls tha1 the current ISO dimensional tolerance (IS0-8062) specifications, which do not include the influence of casting weigh! on feature tole rance, can significantly under- or overes1imate the casting feature variability for small and large castings, respectively. 1

Analysis can also be perfonned to isolate and determine the influence of variou other casting-specific and feature-specific fac­tors on dimensional variabili1y. These factors include shrinkage effects, pattern material and dimension type (e.g., mold-to-mold, mold-to-core. etc.). As an example, the influence of parting line on 1he dimensional variabil ity of cas1ings is summarized for castings made by the three different green sand molding methods. This 1,uggests 1hat almost no additional dimensional variabi lity was ob­served across parting line for vertical parting line molding. However, for horiwntally-parted molds, there is significantly more variability. on average, for dimensions cro sing the parting line (PL).

Average Feature Variability 6cr (mm)

Molding Equipment Crosses PL Not Across PL

high-pressure vertical PL 0.68 high-pressure horizontal PL 1.28 manual jolt squeeze 1.97

0.64 0.80 1.73

Similarly, pattern measurement data can be used to determine the amount of shrinkage that occurs for a specific casting geometry and mold type. Pattern dimensions can be compared to the average of feature dimensions to determine the actual amount of casting shrink­age . Figure I l shows the distribution of shrinkage values for ductile and gray iron features measured. This di stribution suggests a wide range of pattern shrinkage values. Such a wide distribution can be attributed to the many geometry-dependent factors that affect actual ca<;1ing shrinkage values, including mold wall movement, sand

expansion and tbe metal shrinkage, itself. Because of the close attention being paid to controll ing measurement errors, this type of data can be reliably used to develop improved shrinkage allowance guidelines that incorporate the complex feature-dependent nature of casting shrinkage phenomena.

SUMMARY

Current dimensional !Olerance standards for production cas1ings do not provide an accurate picture of the dimensional capabil ities of different casting industry segmcnls. A methodology has been de­scribed to determine foundry dimensional capabilities. Emphasis was laid on analysis of measurement systems to reduce measurement errors to acceptable standards.

These techniques are currently being used in ongoing research to develop improved tolerance guidelines and improved pattern shrink­age allowance estimates for casting industry segments. In addition, the data from participating foundries will be used to deterrnine the process capabilities of individual participating foundries. Methods and procedures have been described to develop dimensional control methodologies and to determine process capabilities. These tech­niques are currently being used to develop improved tolerance guidelines and improved pattern shrinkage allowance estimates for casting industry segments.

REFERENCES

l . ISO 8602: J 994(E), Castings - System of Dimensional Tolerances and Machining Allowances, International Standards Organization (1994).

2. Weiser, P.F., ed., Steel Casting Handbook, 5th ed., Steel Founders' Society of America, Rocky Grove, OH, pp 13-19-13-26 (1980).

3. NADCA, Product Specification Srandardsfor Die Castings, Diecasting Development Council, LaGrange, IL, pp 4-4 - 4- 19 ( 1994).

4. AFS, lnvestmem Casting Handbook, 4th ed., American Foundrymen' s Society, Des Plaines, IL ( 1993).

5. The Aluminum Association, Standards for Aluminum Sand and Penna­nem Mold Castings ( 1988).

6. ISO CD 8062-2, Castings - System of Geometrical Tolerances, Interna­tional Standards Organization ( 1995).

7. A/AG, Measuremem System Analysis-Reference Manual, Automotive Industry Action Group, Southfield, Ml (1995).

Appendices A and 8 follow on next page.

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APPENDIX A

Measurement System Analysis Procedures

Taken from AIAG, Measurement System Analysis - Reference Manual, Automotive Industry Action Group, Southfield, Michigan, 1995.

APPRAISER/ PART AVERAGE

TRIALI 1 2 3 ' 5 6 7 I I 10

I. A 1

2. 2

3. 3

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I . 8 1

7. 2

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Nocn _______________________________ ~

Part No. and Name: Gage Name: Date:

Characteristics: Gage No: Performed by:

Specification: Gage Type:

From data sheet: I • X.,... • R, •

Measurement Unit Analysis ~ Total Variation (TV)

Repeat.ability - Equipment Variation (EV) = 100 [EV /l'Vl EV = tr x K1

%EV Trials K. • 100[_/_J

"' x - - 2 4.56 = 90 - -- 3 3.05

Reproducibility - Appraiser Variation (AV) 'IOAV • 100 [AV/l'Vl

AV = / [(Xorn x KJ' - (EV'/ nr)] -100[._l_ I

= /IL x _J' - L'L x _JJ --"° I Appraisers I 2 I s

n • number of parts

= r = number of trials - I K, I 3.65 I 2.10

Repeatability & Reproducibility (R & R)

R&R = /(EV' + AV') 90 R&R "' 100 [R&R/l'Vl

= 100 [_ /_ J = /L'+_') Parts K,

% = -- 2 3.65

Part Variation (PY) 3 2.70 4 2.30 % PY = 100 [PV/l'Vl

PY • R, x K, 5 :!.08

- x 6 1.93 = 100(_/_ l - - 7 1.82 - 'i"o -- 8 1.74

-

Total Variation (TV) 9 1.67 10 l .62

TV - /(R&.R' + PV') Rx K,

= IL'+_')

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~

~ APPENDIX B (/)

~ Casting and Feature Variable Survey Form QI ::I Ul QI

~ 0 ::I Ul

~

~

Please ci rcle or fill in the most appropriate answer. Add additional comments wherever

necessary.

Foundry Name ------------

Part Number ------------

Approximate number of castings produced per year ____ _

Approximate number of castings produced per lot ____ _

Number of castings per mold Cavity number measured ___ _

If more than one, what is the minimum between spacing ___ _ _

What is the casting used for: automotive, railroad, pump/valve, ---------

Type of flask: tight, slip, flaskless, ------

Mold size (inch x inch) -------

Cope height------ Drag height _____ _

Are jackets used during pouring yes no

Alloy or grade of metal used ------

Pouring temperature range specified High ___ Low

How are the molds weighted during pouring ---------

Type of heat treatment ----------------

Is this casting typically upgraded by straightening yes no

What is the total pour weight-------- units?

What is the finished casting weight ______ _ units?

What 1s the largest dimension on the casting ------- units?

What 1s the wall thickness, if applicable, _____ _ units?

APPENDIX 8 : (CONTINUED)

What is the projected area of casting? _ __ units?

Bounding box that contains casting ? ___ _ units?

How many cores are used -------

What is the total volume of internal coring (inch3

) -----

If shell cores used, what is the specified shell core thickness ___ _ units?

Type(s) of pattern: aluminum, epoxy, wood, iron, steel, bronze, other-------­

Condition of pattern: excellent, very good, good, fair, poor

How old is the pattern equipment (if known) ------

Type of pattern set-up: matchplate, separate cope & drag, loose, other-------­

Type of molding sand: green, no-bake, shell, other----------

What is the assigned Sand System Number (SSN) ____ _

Is facing sand used yes I no

If yes what is the Facing Sand System Number (FSSN) __

If flask used, how often are the pins and bushings on flasks checked ___ _

Molding method: jolt squeeze, slinger, hand rammed, automatic ( type --------

other __________________ _

What type of chills used: none used, nails, block (size) , other ______ _

Is mold wash used yes no

Please add any comments about binders, additives, process controls, etc. or anything of

relevance that has not been included:

I

I I

I I

I I

I I

I I

I I

I I

I I

I I

I

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Appendix B, continued.

Casting Variables Survey Form ,_ .... _ ...... ~.., .................... Variables Soecif

feature number

d11nens1on location cope.drag.across PL

direction of the d11nens1on

do chills affect this feature dimension

does draft affect this leature

does grinding affect thlS feature• •

does mold wash affect this feature

1s this d1rnens1on upgraded by straightening• •

what 1s the nominal dimension

what 1s the total tolerance

what is the mold/core relationship

type of core used for this feature

what 1s the Core System No

how are the cores made

are the cores lightened

how are the cores set

does d imension cross core parting line

1s d1mens1on part of a core assembly

does d1mens1on cross core assembly 101n1

os a core assembly fi xture used

does core wash alfect 1h1s Jeature

type of core box used to manufacture core

cond1t1on of core box

NOTE 1f this dimension is upgraded by s1fa;ghten1ng or grinding then lhe mspecitan should takeplace belorehand

D -----,... --c-·.1 ~- -A

;_., [.:: . I 'l ~, , . I

;<f--- H --~ ~G~

F~ ;E--E:

A: mold-to-mold, across casting

B: mold-to-mold, across mold

C: mold-to-mold, across mold and casting

D: mold-to-mold, across casting/mold/casting

E: mold-to-core, across casting

F: core-to-core, across core

G: mold-to-core, across casting and core

H: mold-to-mold, across casting/core/casting

I: core-to-core, across casting

0 : other configurations ??