Designation:A159–83(Reapproved2001)
Standard Specification for
Automotive Gray Iron Castings1
This standard is issued under thefixed designation A159;the number immediately following the designation indicates the year of
original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A
superscript 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.This specification replaces Federal specification
AA-I-653A.
1.Scope
1.1This specification applies to gray iron castings,cast in
sand molds,used in the products of the automobile,truck,
tractor,and allied industries.
1.2The values stated in inch-pound units are to be regarded
as the standard.
2.Referenced Documents
2.1The following documents of the issue in effect on the
date of material procurement form a part of this specification to
the extent referenced herein:
2.2ASTM Standards:
A247Test Method for Evaluating the Microstructure of
Graphite in Iron Castings2
E10Test Method for Brinell Hardness of Metallic Materi-als3
2.3Military Standard:
MIL-STD-129Marking for Shipment and Storage4
2.4Federal Standard:
Fed.Std.No.123Marking for Shipment(Civil Agencies)4
3.Grades
3.1The specified grades,hardness ranges,and metallurgical description are shown in Table1and Table2and in Section9.
4.Ordering Information
4.1Orders for materials under this specification shall in-clude the following information:
4.1.1ASTM designation,
4.1.2Grade designation of gray iron required(3.1),
4.1.3If special heat treatment is required(see Section6), 4.1.4If special microstructure requirements are needed(see Section7),
4.1.5Surface where hardness test is to be performed(see 9.4),
4.1.6Depth and surface hardness of case required(see9.6), 4.1.7Inspection lot and sampling plan required(see Section 10),
4.1.8If additional requirements are needed(see11.3),and 4.1.9Whether special packaging and marking is required (see Section12).
5.Hardness
5.1The foundry shall exercise the necessary controls and inspection techniques to ensure compliance with the specified hardness range,Brinell hardness shall be determined in accor-dance with Test Method E10,after sufficient material has been removed from the casting surface to ensure representative hardness readings.The10-mm ball and3000-kg load shall be used unless otherwise agreed upon.The area or areas on the casting where hardness is to be checked shall be established by agreement between supplier and purchaser and shall be shown on the drawing.
6.Heat Treatment
6.1Unless otherwise specified,castings of Grades G1800 and G2500may be annealed in order to meet the desired hardness range.
6.2Appropriate heat treatment for removal of residual stresses,or to improve machinability or wear resistance may be specified by agreement between supplier and purchaser.
1This specification is under the jurisdiction of ASTM Committee A04on Iron Castings and is the direct responsibility of Subcommittee A04.01on Gray and White Iron Castings.
Current edition approved July29,1983.Published September1983.Originally published as A159–35T.Last previous edition A159–77.
2Annual Book of ASTM Standards,V ol01.02.
3Annual Book of ASTM Standards,V ol03.01.
4Available from Standardization Documents Order Desk,Bldg.4Section D,700 Robbins Ave.,Philadelphia,PA19111-5094,Attn:NPODS.
TABLE1Grades of Gray Iron
Grade Casting Hardness Range Description
G1800HB187max
4.4BID min or as agreed A
ferritic-pearlitic
G2500HB170-229
4.6–4.0BID or as agreed A
pearlitic-ferritic
G3000HB187-241
4.4–3.9BID or as agreed A
pearlitic
G3500HB207-255
4.2–3.8BID or as agreed A
pearlitic
G4000HB217-269
4.1–3.7BID or as agreed A
pearlitic
A Brinell impression diameter(BID)is the diameter in millimetres of the impres-
sion of a10mm ball at3000-kg load.
1
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7.Microstructure
7.1The microstructure shall consist of flake graphite in a matrix of ferrite or pearlite or mixtures thereof.
7.2As graphite size and shape somewhat affect hardness-strength ratio and other properties,the type size and distribu-tion of the graphite flakes at a designated location on the casting may be specified by agreement between supplier and purchaser in accordance with Method A 247.
7.3Unless otherwise specified,the matrix microstructure of castings covered by this specification shall be substantially free of primary cementite.Castings in Grades G1800and G2500may have a matrix of ferrite or pearlite or both.Grades G3000,G3500,and G4000shall be substantially pearlite in matrix structure.
8.Heavy-Duty Brake Drums and Clutch Plates
8.1These castings are considered as special cases and are covered in Table 2.
9.Alloy Gray Iron Automotive Camshafts
9.1These castings are considered as special cases.9.2Grade Designation —G4000d.
9.3Chemistry —Alloy gray iron camshafts shall contain alloys within the following range or as agreed upon between supplier and purchaser.
Chromium 0.85–1.25%Molybdenum 0.40–0.60%Nickel
as agreed
9.4Casting Hardness —HB 241-321determined on a bear-ing surface as agreed by supplier and purchaser.
9.5Microstructure —Extending 45°on both sides of the centerline of the cam nose and to a minimum depth of 1/8in.(3.2mm),the surface shall consist of primary carbides (of acicular or cellular form or a mixture thereof)and graphite in a fine pearlitic matrix.The graphite shall be Type VII A and E distribution,4to 7flake size in accordance with Method A 247.The amount of primary carbides and location at which the structure is checked shall be a matter of agreement between the supplier and the purchaser.
9.6Selective Hardening —The cam areas of camshaft cast-ing are usually selectively hardened by flame or induction
hardening by the supplier.The depth and surface hardness of the hardened case shall be as agreed upon between supplier and purchaser.
10.Quality Assurance Provisions
10.1Responsibility for Inspection —Unless otherwise speci-fied in the contract or purchase order,the producer is respon-sible for the performance of all inspection and tests require-ments specified in this specification.Except as otherwise specified in the contract or purchase order,the producer may use his own or any other suitable facilities for the performance of the inspection and test requirements specified herein,unless disapproved by the purchaser.The purchaser shall have the right to perform any of the inspection and tests set for in this specification where such inspections are deemed necessary to assure that material conform to prescribed requirements.
10.2Lot —For the purpose of inspection,lot and sampling plans shall be agreed upon between the purchaser and the producer.
11.General
11.1Castings furnished to this specification shall be repre-sentative of good foundry practice and shall conform to dimensions and tolerances specified on the casting drawing.11.2Minor imperfections usually not associated with the structural function may occur in castings.These are often repairable but repairs shall be made only where allowed by the purchaser and only by approved methods.
11.3Additional casting requirements may be agreed upon by purchaser and supplier.These should appear as product specifications on the casting or part drawing.
12.Preparation for Delivery
12.1Unless otherwise specified in the contract or purchase order,castings shall be cleaned,preserved,and packaged in accordance with supplier’s standard commercial practice.12.2Government Procurement —When specified for Gov-ernment procurement,castings shall be marked for shipment in accordance with MIL-STD-129for military procurement and Fed.Std.No.123for civil agency procurement.
TABLE 2Brake Drums and Clutch Plates for Special Service
Grade
Carbon min,%Aeditor evaluating revision
Casting Hardness
Microstructure
Graphite
Matrix
G2500a    3.40HB 170-229
4.6–4.0BID or as agreed Type VII,size 2–4B A distribution
lamellar pearlite
ferrite if present not to exceed 15%G3500b    3.40C HB 207-255
4.2–3.8BID or as agreed Type VII,size 3–5B A distribution
lamellar pearlite
ferrite or carbide if present not to exceed 5%G3500c
3.50C
HB 207-255
4.2–3.8BID or as agreed
Type VII,size 3–5B A distribution
lamellar pearlite
ferrite or carbide,if present not to exceed 5%
A
The chemical analysis for total carbon shall be made on chilled pencil-type specimens or from thin wafers approximately 1/32in.(0.8mm)thick cut from test coupons.Drillings are not reliable because of the probable loss of graphite.B
See Method A 247.C
Grades G 3500b and G 3500c normally require alloying to obtain the specified hardness at the high carbon levels
specified.
APPENDIX
(Nonmandatory Information)
X1.GRAY IRON
X1.1Definition
X1.1.1gray iron —a cast iron in which the graphite is present as flakes instead of temper carbon nodules as in malleable iron or small spherulites as in ductile iron.X1.2Chemical Composition
X1.2.1The ranges in composition generally employed in producing the various grades of most automotive gray iron castings are shown in Table X1.1.The composition ranges for such special applications as heavy duty brake drums and clutch plates and camshafts are shown in Table X1.2and Table X1.3,respectively.The contents of certain elements for these appli-cations are critical in terms of service requirements and the ranges are specified in the standard.
X1.2.2The specific composition range for a given grade may vary according to the prevailing or governing section of the castings being produced.
X1.2.3Alloying elements such as chromium,copper,nickel,tin,molybdenum,or other elements may be employed to meet the specified hardness or microstructural requirements or to provide the properties needed for particular service conditions.
X1.3Microstructure
X1.3.1The microstructure of the various grades of gray iron are generally a mixture of flake graphite in
a matrix of ferrite,pearlite,or tempered pearlite.The relative amounts of each of these constituents depends on the analysis of the iron,casting design,and foundry techniques as they affect solidification and subsequent cooling rate and heat treatments if any.
X1.3.2The distribution and size of graphite flakes like the matrix structure of gray iron depends greatly on the solidifi-cation rate and cooling rate of the casting.If a section solidifies very rapidly an appreciable amount of carbide causing a mottled fracture or chilled corners can be present.If a section cools slowly,as in a massive heavy-section casting,an appre-ciable amount of ferrite may be present.In like manner,light sections will contain small graphite flakes while graphite will form in much larger flakes if the same iron is poured into a heavy casting.
X1.3.3For these reasons the strength and hardness of gray iron are greatly influenced by the rate of cooling during and
after solidification,the design and nature of the mold and the casting,and by other factors such as inoculation practice in addition to the composition of the iron.
X1.3.4Alloying with nickel,chromium,molybdenum,tin,copper or other alloys usually promotes a more stable pearlitic structure and is often done to obtain increased hardness,strength,and wear resistance
especially in heavy sections subjected to severe service.
X1.3.5Alloying is sometimes used to obtain structures containing a controlled percentage of carbides as in camshaft or valve lifter castings.
X1.3.6Primary carbides or pearlite or both,can be decom-posed by appropriate heat treatment.Gray irons of suitable composition and structure can be hardened by liquid quenching or by flame or induction selective hardening.
X1.4Mechanical Properties
X1.4.1The mechanical properties listed in Table X1.4can
TABLE X1.1Typical Base Compositions,%
Grade
Carbon
Silicon
Manganese
Sulfur,max
Phosphorus,max
Approximate Carbon
Equivalent G1800  3.40–3.70  2.30–2.800.50–0.800.150.25  4.25–4.5G2500  3.20–3.50  2.00–2.400.60–0.900.150.20  4.0–4.25G3000  3.10–3.40  1.90–2.300.60–0.900.150.15  3.9–4.15G3500  3.00–3.30  1.80–2.200.60–0.900.150.12  3.7–3.9G4000  3.00–3.30  1.80–2.100.70–1.000.150.10
3.7–3.9(usually alloyed)
TABLE X1.2Usual Composition of Brake Drums and Clutch
Plates for Special Service
Chemical Compo-sition,%Grade G2500a Grade G3500b Grade G3500c Carbon,total (mandatory)  3.40min    3.40min    3.50min Silicon (as required)
1.60–
2.10  1.30–1.80  1.30–1.80Manganese (as required)0.60–0.900.60–0.900.60–0.90Sulfur,max
0.120.120.12Phosphorus,max 0.150.150.15Alloys
as required
as required
as required
TABLE X1.3Usual Chemical Composition of Alloy Gray Iron
Automotive Camshafts
Grade G4000d,%
Total carbon    3.10–3.60Silicon
1.95–
2.40Manganese 0.60–0.90Phosphorus 0.10max Sulfur 0.15max Chromium 0.85–1.25Molybdenum 0.40–0.60
Nickel 0.20–0.45optional Copper
residual
be used for design purposes.However,the suitability of a particular grade for an intended application is best determined by laboratory or service tests.Typical mechanical properties for such specialized applications as heavy-duty brake drums and clutch plates are shown in Table X1.5.
X1.5Application of Gray Iron in Automotive Castings (see Table X1.6)
X1.5.1The graphiteflakes in gray iron give this metal many desirable properties.These include excellent machinability, high thermal conductivity,vibration dampening properties,and resistance to wear or scuffing.Due to its low freezing tempera-ture for a ferrous alloy,highfluidity,and low shrinkage properties it is more readily cast in complex shapes than other ferrous metals.
X1.5.2Gray iron castings of the lower-strength Grades
G1800and G2500are characterized by excellent machinabil-ity,high damping capacity,low modulus of elasticity,and comparative ease of manufacture.When higher strength is obtained by a reduction in the carbon or carbon equivalent, castings are more difficult to machine,have lower damping capacity,higher modulus of elasticity,and may be more difficult to manufacture.
X1.6Special Applications of Gray Iron
X1.6.1Heavy-Duty Brake Drums and Clutch Plates Automotive brake drums and clutch plates for heavy-duty service are considered as special cases.Typical chemical analyses and mechanical properties are listed in Table X1.2and Table X1.5.Heavy-duty irons for such service require high carbon contents for resistance to thermal shock and to mini-mize heat checking.To maintain strength levels specified for Grades G3500b and G3500c normally requires alloying due to their high carbon contents.
X1.6.2Microstructure
See Table2for microstructure requirements.
X1.6.3Suggested Usage
Following are suggested grades for brake drums and clutch plates according to types of service:
Grade Suggested Usage
G2500a Brake drums and clutch plates for moderate service require-
ments,where high carbon iron is desired to minimize heat
checking(see Section8).
G3500b Brake drums and clutch plates for heavy-duty service where
both resistance to heat checking and higher strength are definite
requirements(see Section8).
G3500c Extra-heavy-duty service brake drums(see Section8).
X1.7Automotive Camshafts
X1.7.1Alloy gray iron automotive camshafts are also con-sidered as special cases.The chemical composition of such castings is usually within the range given in Table X1.3but may be modified by mutual agreement.
X1.7.2In casting hardenable iron from camshafts,the aim is to obtain a suitable microstructure in critical locations of the casting and balance the composition to obtain response to induction orflame-hardening treatment.These depend not only on the chemistry of the iron but even more on the cross section
TABLE X1.4Mechanical Properties for Design Purposes
Grade Hardness Range A Tensile Strength,min,psi
(kgf/mm2)Transverse Strength,
min,lb(kg)B
Deflection,min,in.
(mm)B
G1800HB143-18718000(14)1720(780)0.14(3.6)
5.0–4.4BID
G2500HB170-22925000(17.5)2000(910)0.17(4.3)
4.6–4.0BID
G3000HB187-24130000(21)2200(1000)0.20(5.1)
4.4–3.9BID
G3500HB207-25535000(24.5)2450(1090)0.24(6.1)
4.2–3.8BID
G4000HB217-26940000(28)2600(1180)0.27(6.9)
4.1–3.7BID
A Brinell impression diameter(BID)is the diameter in millimetres of the impression of a10-mm ball at3000-kg load.
B See Method A438for information concerning the B transverse test bar and the transverse test.
TABLE X1.5Typical Mechanical Properties
Mechanical Properties
Grade
G2500a
Grade
G3500b
Grade
G3500c
Tensile strength,min:
psi250003500035000 kgf/mm217.524.524.5 Transverse strength,min:
lb200024002400 kg91010901090 Deflection,min:
in.0.170.240.24 mm  4.3  6.1  6.1 Hardness,HB170–229207–255207–255 Brinell indention diameter,mm  4.6–4.0  4.2–3.8  4.2–3.8TABLE X1.6Typical Applications of Gray Iron for Automotive
Castings
Grade General Data
G1800Miscellaneous soft iron castings(as cast or annealed)in which strength is not of primary consideration.Exhaust manifolds may be
made of this grade of iron,alloyed or unalloyed.These may be
annealed castings for exhaust manifolds in order to avoid growth
and cracking due to heat.
G2500Small cylinder blocks,cylinder heads,air cooled cylinders,pistons, clutch plates,oil pump bodies,transmission cases,gear boxes,
clutch housings,and light-duty brake drums.
G3000Automobile and diesel cylinder blocks,cylinder heads,flywheels, differential carries castings,pistons,medium-duty brake drums,and
clutch plates.
G3500Diesel engine blocks,truck and tractor cylinder blocks and heads, heavyflywheels,tractor transmission cases,and heavy gear boxes. G4000Diesel engine castings,liners,cylinders,and
pistons.
of the casting and details of melting practice.In making a given casting,it is recognized that the foundry willfind it necessary to adjust the chemistry to narrower limits within the range of analysis in Table X1.3.
X1.7.3As the performance of an automotive camshaft is determined by the microstructure and hardness,producers do not normally use tensile or transverse tests for quality control purposes.Camshaft iron with chemistry as given in Table X1.3 would be expected to have the following minimum mechanical properties.
Tensile strength,min:
psi40000
kgf/mm228
Transverse strength,min:
lb2600
kg1180
Deflection,min:
in.0.27
mm  6.9
Hardness,HB241–321
BID  3.9–3.4
X1.7.4Microstructure——See9.5for microstructure re-quirements for Grade G4000d alloy cast iron camshafts.
X1.8Additional Information
X1.8.1Additional information concerning gray iron cast-ings,their properties and uses can be obtained from the following sources:
(1)Metals Handbook,8th Edition,V ols1,2,and5,published
by the American Society for Metals,Metals Park,Ohio.
(2)Cast Metals Handbook published by the American Found-
rymen’s Society,Des Plaines,Ill.
(3)Gray&Ductile Iron Castings Handbook(1971)published
by Gray and Ductile Iron Founders Society,Cleveland, Ohio.
(4)Physical and Engineering Properties of Cast Iron,Angus,
British Cast Iron Research Association(1960),Alve-church,Birmingham,England.
(5)Engineering Data on Gray Cast Irons,G.N.J.Gilbert
British Cast Iron Research Association(1968),Alve-church,Birmingham,England.
(6)Gray,Ductile and Malleable,Iron Castings Current Ca-
pabilities.ASTM STP455,(1969).
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