ASTM A48/A48M-03

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Designation: A 48/A 48M – 03
Standard Specification for
Gray Iron Castings
This standard is issued under the fixed designation A 48/A 48M; 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
QQ-I-652.
1. Scope 3.1.1 Definitions for many terms common to gray iron
castings are found in Terminology A 644.
1.1 This specification covers gray iron castings intended for
general engineering use where tensile strength is a major
4. Classification
consideration. Castings are classified on the basis of the tensile
4.1 Castings ordered and produced in accordance with this
strength of the iron in separately cast test bars.
specificationareclassifiedintoanumberofgradesbasedonthe
1.1.1 This specification subordinates chemical composition
properties of separately cast test bars (Table 1, Table 2). Each
to tensile strength.
class is designated by a number followed by a letter. The
1.2 Castings produced to this specification are graded on the
number indicates the minimum tensile strength of the sepa-
basis of minimum tensile strength obtained in special test
rately cast test bar, and the letter indicates the size of the test
coupons designed to standardize cooling rate. The tensile
bar. Examples of proper designations are as follows:
strength developed in certain casting sections may vary from
Gray Iron Castings, ASTM Specification A 48, Class 30B.
test coupon values (see X1.2).
Gray Iron Castings, ASTM Specification A 48, Class 40C.
1.3 The values stated in either inch-pound units or SI units
are to be regarded separately as standard. Within the text, the
5. Ordering Information
SI units are shown in brackets. The values stated in each
5.1 Orders for material to this specification shall include the
system are not exact equivalents; therefore, each system shall
following information:
be used independently of the other. Combining values from the
5.1.1 ASTM designation number and year of issue,
two systems may result in nonconformance with the specifi-
5.1.2 Class of iron required (see 4.1, Table 1, and Table 2),
cation.
5.1.3 The size of the separately cast test bar (letter
classification—A, B, C, or S) that best represents the thickness
2. Referenced Documents
of the controlling section of the casting (see Table 3),
2.1 ASTM Standards:
5.1.4 The tension test specimen (B or C) to be machined
A 644 Terminology Relating to Iron Castings
from test bar C (see 13.3, Table 4, and Fig. 1),
E 8 Test Methods for Tension Testing of Metallic Materials
5.1.5 The tension test specimen to be machined from test
2.2 Military Standard:
2 bar S (see 13.4, Table 4, and Fig. 1),
MIL-STD-129 Marking for Shipment and Storage
5.1.6 Lot size (see Section 10),
2.3 Federal Standard:
5.1.7 Special requirements (see Section 6),
Federal Standard No. 123 Marking for Shipment (Civil
2 5.1.8 Saving tested specimens or unbroken test bars (see
Agencies)
15.1), and
3. Terminology 5.1.9 Special preparation for delivery (see Section 19).
3.1 Definitions:
6. Special Requirements
6.1 When agreed upon in writing between the manufacturer
This specification is under the jurisdiction of ASTM Committee A04 on Iron
and the purchaser, it may be necessary for the castings to meet
Castings and is the direct responsibility of Subcommittee A04.01 on Gray Iron
special requirements as to hardness, chemical composition,
Castings.
microstructure, pressure tightness, radiographic soundness,
Current edition approved Dec. 1, 2003. Published January 2004. Originally
approved in 1905. Last previous edition approved in 2000 as A 48 – 00. dimensions, surface finish, and so forth.
Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700
Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A 48/A 48M – 03
TABLE 1 Requirements for Tensile Strength of Gray Cast Irons TABLE 2 Requirements for Tensile Strength of Gray Cast Irons
in Separately Cast Test Bars (Inch-Pound) in Separately Cast Test Bars (Metric)
Tensile Strength, Nominal Test Bar Tensile Strength, Nominal Test Bar
Class Class
min, ksi Diameter, in. min, ksi [MPa] Diameter, in. [mm]
No. 20 A 20 0.8 No. 150A 150 20 to 22
No. 20 B 1.2 No. 150B 30
No. 20 C 2.0 No. 150C 50
A A
No. 20 S Bars S No. 150S Bars S
No. 25 A 25 0.88 No. 175A 175 20 to 22
No. 25 B 1.2 No. 175B 30
No. 25 C 2.0 No. 175C 50
A A
No. 25 S Bars S No. 175S Bars S
No. 30 A 30 0.88 No. 200A 200 20 to 22
No. 30 B 1.2 No. 200B 30
No. 30 C 2.0 No. 200C 50
A A
No. 30 S Bars S No. 200S Bars S
No. 35 A 35 0.88 No. 225A 225 20 to 22
No. 35 B 1.2 No. 225B 30
No. 35 C 2.0 No. 225C 50
A A
No. 35 S Bars S No. 225S Bars S
No. 40 A 40 0.88 No. 250A 250 20 to 22
No. 40 B 1.2 No. 250B 30
No. 40 C 2.0 No. 250C 50
A A
No. 40 S Bars S No. 250S Bars S
No. 45 A 45 0.88 No. 275A 275 20 to 22
No. 45 B 1.2 No. 275B 30
No. 45 C 2.0 No. 275C 50
A A
No. 45 S Bars S No. 275S Bars S
No. 50 A 50 0.88 No. 300A 300 20 to 22
No. 50 B 1.2 No. 300B 30
No. 50 C 2.0 No. 300C 50
A A
No. 50 S Bars S No. 300S Bars S
No. 55 A 55 0.88 No. 325A 325 20 to 22
No. 55 B 1.2 No. 325B 30
No. 55 C 2.0 No. 325C 50
A A
No. 55 S Bars S No. 325S Bars S
No. 60 A 60 0.88 No. 350A 350 20 to 22
No. 60 B 1.2 No. 350B 30
No. 60 C 2.0 No. 350C 50
A A
No. 60 S Bars S No. 350S Bars S
A
AlldimensionsoftestbarSshallbeasagreeduponbetweenthemanufacturer
No. 375A 375 20 to 22
and the purchaser.
No. 375B 30
No. 375C 50
A
No. 375S Bars S
7. Tensile Requirements
No. 400A 400 20 to 22
7.1 Test bars representing castings conforming to this speci-
No. 400B 30
No. 400C 50
fication shall meet the requirements for tensile strength as
A
No. 400S Bars S
described in Table 1 and Table 2.
A
AlldimensionsoftestbarSshallbeasagreeduponbetweenthemanufacturer
and the purchaser.
8. Dimensional Requirements
8.1 The castings shall conform to the dimensions or draw-
ings furnished by the purchaser, or, if there are no drawings, to
10. Sampling
the dimensions predicted by the pattern equipment supplied by
10.1 A lot shall consist of one of the following:
the purchaser.
10.1.1 All the metal poured from a single heating in a batch
9. Workmanship and Finish
type melting furnace.
10.1.2 All the metal from two or more batch type melting
9.1 The surface of the casting shall be free of adhering sand,
furnaces poured into a single ladle or a single casting.
scale, cracks, and hot tears, as determined by visual examina-
tion. 10.1.3 All the metal poured from a continuous melting
9.2 No repairing by plugging or welding of any kind shall furnace for a given period of time between changes in charge,
be permitted unless written permission is granted by the processing conditions, or aim-for chemistry or 4 h, whichever
purchaser. is the shorter period.
A 48/A 48M – 03
TABLE 3 Separately Cast Test Bars for Use When a Specific
12.2 One tension test shall be performed on each lot and
Correlation Has Not Been Established Between the Test Bar and
shall conform to the tensile requirements specified.
the Casting
12.3 If the results of a valid test fail to conform to the
Thickness of the Wall of the Controlling
Test Bar requirements of this specification, two retests shall be made. If
Section of the Casting, in. [mm]
either retest fails to meet the specification requirements, the
Under 0.25 [under 5] S
castings represented by these test specimens shall be rejected.
0.25 to 0.50 [5 to 14] A
0.51 to 1.00 [15 to 25] B A valid test is one wherein the specimen has been properly
1.01 to 2 [26 to 50] C
prepared and appears to be sound and on which the approved
Over 2 [over 50] S
test procedure has been followed.
12.4 Ifsufficientseparatelycasttestpiecesarenotavailable,
the manufacturer shall have the option of removing a test
specimen from a location of representative casting, as agreed
10.1.3.1 The purchaser may agree to extend the 4-h time
upon between the manufacturer and purchaser.
period to8hifthe manufacturer can demonstrate sufficient
12.5 If the first test results indicate that a heat treatment is
process control to warrant such an extension.
needed to meet the test requirements, the entire lot of castings
and the representative test specimens shall be heat treated
11. Cast Test Bars
together. Testing shall proceed in accordance with 12.1-12.3.
11.1 Test bars shall be separate castings poured from the
12.6 If, after testing, a test specimen shows evidence of a
same lot as the castings they represent and shall have dimen-
defect, the results of the test may be invalidated and another
sions as shown in Table 4. Allowance may be made for
made on a specimen from the same lot.
reasonable pattern draft within the tolerances shown inTable 4.
Test bars A, B, and C are all standard test bars in the form of
13. Tension Test Specimens
simple cylinders. Test bar S is special and is intended for use
13.1 For test Bar A, the tension-test specimen A, as shown
where the standard bars are not satisfactory.
in Fig. 1, shall be machined concentric with the axis of the test
11.2 The test bars shall be cast in dried, baked, or chemi-
bar.
cally bonded molds made mainly of an aggregate of siliceous
13.2 For test Bar B, the tension test specimen B, as shown
sand with appropriate binders. The average grain size of the
in Fig. 1, shall be machined concentric with the axis of the test
sand shall approximate that of the sand in which the castings
bar.
are poured. Molds for the test bars shall be approximately at
13.3 For test Bar C, tension test specimens B or C, as shown
room temperature when poured. More than one test bar may be
in Fig. 1, shall be machined concentric with the axis of the test
cast in a single mold, but each bar in the mold shall be
bar.Unlessthesizeofthetensiontestspecimentobemachined
surrounded by a thickness of sand which is not less than the
from test bar C is specified in writing by the purchaser, the
diameter of the bar. A suitable design for a m
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