Standard Specification for Gray Iron Castings

SCOPE
1.1 This specification covers gray iron castings intended for general engineering use where tensile strength is a major consideration. Castings are classified on the basis of the tensile strength of the iron in separately cast test bars.  
1.1.1 This specification subordinates chemical composition to tensile strength.  
1.2 Castings produced to this specification are graded on the basis of minimum tensile strength obtained in special test coupons designed to standardize cooling rate. The tensile strength developed in certain casting sections may vary from test coupon values (see X1.2).  
1.3 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.

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ASTM A48-94ae1 - Standard Specification for Gray Iron Castings
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
e1
Designation: A 48 – 94a
Standard Specification for
Gray Iron Castings
This standard is issued under the fixed designation A 48; 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.
e NOTE—Note 1 was added editorially in September 1998.
1. Scope 3. Terminology
1.1 This specification covers gray iron castings intended for 3.1 Definitions:
general engineering use where tensile strength is a major 3.1.1 Definitions for many terms common to gray iron
consideration. Castings are classified on the basis of the tensile castings are found in Terminology A 644.
strength of the iron in separately cast test bars.
4. Classification
1.1.1 This specification subordinates chemical composition
4.1 Castings ordered and produced in accordance with this
to tensile strength.
1.2 Castings produced to this specification are graded on the specification are classified into a number of grades based on the
properties of separately cast test bars (Table 1). Each class is
basis of minimum tensile strength obtained in special test
coupons designed to standardize cooling rate. The tensile designated by a number followed by a letter. The number
indicates the minimum tensile strength of the separately cast
strength developed in certain casting sections may vary from
test coupon values (see X1.2). test bar, and the letter indicates the size of the test bar.
Examples of proper designations are as follows:
1.3 The values stated in inch-pound units are to be regarded
as the standard. The values given in parentheses are for Gray Iron Castings, ASTM Specification A 48, Class 30B.
Gray Iron Castings, ASTM Specification A 48, Class 40C.
information only.
NOTE 1—The text of this standard references notes and footnotes which
5. Ordering Information
provide explanatory material. These notes and footnotes (excluding those
5.1 Orders for material to this specification shall include the
in tables and figures) shall not be considered as requirements of the
following information:
standard.
5.1.1 ASTM designation number and year of issue,
2. Referenced Documents
5.1.2 Class of iron required (see 4.1 and Table 1),
2.1 ASTM Standards: 5.1.3 The size of the separately cast test bar (letter
classification—A, B, C, or S) that best represents the thickness
A 644 Terminology Relating to Iron Castings
E 8 Test Methods for Tension Testing of Metallic Materials of the controlling section of the casting (see Table 2),
5.1.4 The tension test specimen (B or C) to be machined
2.2 Military Standard:
MIL-STD-129 Marking for Shipment and Storage from test bar C (see 13.3, Table 3, and Fig. 1),
5.1.5 The tension test specimen to be machined from test
2.3 Federal Standard:
Federal Standard No. 123 Marking for Shipment (Civil bar S (see 13.4, Table 3, and Fig. 1),
5.1.6 Lot size (see Section 10),
Agencies)
5.1.7 Special requirements (see Section 6),
5.1.8 Saving tested specimens or unbroken test bars (see
This specification is under the jurisdiction of ASTM Committee A-4 on Iron
15.1), and
Castings and is the direct responsibility of Subcommittee A04.01 on Gray Iron
5.1.9 Special preparation for delivery (see Section 19).
Castings.
Current edition approved July 15, 1994. Published September 1994. Originally
6. Special Requirements
published as A 48 – 05. Last previous edition A 48 – 94.
Annual Book of ASTM Standards, Vol 01.02.
6.1 When agreed upon in writing between the manufacturer
Annual Book of ASTM Standards, Vol 03.01.
4 and the purchaser, it may be necessary for the castings to meet
Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700
Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS. special requirements as to hardness, chemical composition,
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
e1
A 48 – 94a
TABLE 1 Requirements for Tensile Strength of Gray Cast Irons
8. Dimensional Requirements
in Separately Cast Test Bars
8.1 The castings shall conform to the dimensions or draw-
ings furnished by the purchaser, or, if there are no drawings, to
Tensile Strength, Nominal Test Bar
Class
min, ksi (MPa) Diameter, in. (mm)
the dimensions predicted by the pattern equipment supplied by
No. 20 A 20 (138) 0.88 (22.4) the purchaser.
No. 20 B 1.2 (30.5)
No. 20 C 2.0 (50.8)
9. Workmanship and Finish
A
No. 20 S Bars S
9.1 The surface of the casting shall be free of adhering sand,
No. 25 A 25 (172) 0.88 (22.4)
scale, cracks, and hot tears, as determined by visual examina-
No. 25 B 1.2 (30.5)
tion.
No. 25 C 2.0 (50.8)
A
9.2 No repairing by plugging or welding of any kind shall
No. 25 S Bars S
be permitted unless written permission is granted by the
No. 30 A 30 (207) 0.88 (22.4)
purchaser.
No. 30 B 1.2 (30.5)
No. 30 C 2.0 (50.8)
10. Sampling
A
No. 30 S Bars S
10.1 A lot shall consist of one of the following:
No. 35 A 35 (241) 0.88 (22.4)
10.1.1 All the metal poured from a single heating in a batch
No. 35 B 1.2 (30.5)
No. 35 C 2.0 (50.8) type melting furnace.
A
No. 35 S Bars S
10.1.2 All the metal from two or more batch type melting
furnaces poured into a single ladle or a single casting.
No. 40 A 40 (276) 0.88 (22.4)
No. 40 B 1.2 (30.5) 10.1.3 All the metal poured from a continuous melting
No. 40 C 2.0 (50.8)
furnace for a given period of time between changes in charge,
A
No. 40 S Bars S
processing conditions, or aim-for chemistry or 4 h, whichever
No. 45 A 45 (310) 0.88 (22.4) is the shorter period.
No. 45 B 1.2 (30.5)
10.1.3.1 The purchaser may agree to extend the 4-h time
No. 45 C 2.0 (50.8)
A period to8hifthe manufacturer can demonstrate sufficient
No. 45 S Bars S
process control to warrant such an extension.
No. 50 A 50 (345) 0.88 (22.4)
No. 50 B 1.2 (30.5)
11. Cast Test Bars
No. 50 C 2.0 (50.8)
A
11.1 Test bars shall be separate castings poured from the
No. 50 S Bars S
same lot as the castings they represent and shall have dimen-
No. 55 A 55 (379) 0.88 (22.4)
sions as shown in Table 3. Allowance may be made for
No. 55 B 1.2 (30.5)
reasonable pattern draft within the tolerances shown in Table 3.
No. 55 C 2.0 (50.8)
A
No. 55 S Bars S
Test bars A, B, and C are all standard test bars in the form of
simple cylinders. Test bar S is special and is intended for use
No. 60 A 60 (414) 0.88 (22.4)
where the standard bars are not satisfactory.
No. 60 B 1.2 (30.5)
No. 60 C 2.0 (50.8)
11.2 The test bars shall be cast in dried, baked, or chemi-
A
No. 60 S Bars S
cally bonded molds made mainly of an aggregate of siliceous
A
All dimensions of test bar S shall be as agreed upon between the manufacturer
sand with appropriate binders. The average grain size of the
and the purchaser.
sand shall approximate that of the sand in which the castings
are poured. Molds for the test bars shall be approximately at
TABLE 2 Separately Cast Test Bars for Use When a Specific
room temperature when poured. More than one test bar may be
Correlation Has Not Been Established Between the Test Bar and
the Casting cast in a single mold, but each bar in the mold shall be
surrounded by a thickness of sand which is not less than the
Thickness of the Wall of the Controlling
diameter of the bar. A suitable design for a mold is shown in
Test Bar
Section of the Casting, in. (mm)
Fig. 2.
Under 0.25 (6) S
0.25 to 0.50 (6 to 12) A NOTE 2—The intent of these provisions is as follows: to prohibit the
0.51 to 1.00 (13 to 25) B
casting of test bars in molds of metal, graphite, zircon, light-weight
1.01 to 2 (26 to 50) C
aggregates, or other materials which would significantly affect the tensile
Over 2 (50) S
strength of the iron; to prohibit control of tensile strength of the test bars
by manipulation of the grain size of the sand; and to prohibit the casting
of test bars in molds preheated substantially above room temperature.
microstructure, pressure tightness, radiographic soundness,
11.3 Test bars that are intended to represent castings that are
dimensions, surface finish, etc.
cooled in the mold to less than 900°F (480° C), before
shakeout, shall be cooled in their molds to a temperature less
7. Tensile Requirements
than 900°F (480° C). They then may be cooled in still air to
7.1 Test bars representing castings conforming to this speci- room temperature.
fication shall meet the requirements for tensile strength as 11.4 Test bars that are intended to represent castings that are
described in Table 1. hotter than 900°F (480° C), when shaken out of their molds,
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
e1
A 48 – 94a
TABLE 3 Diameters and Lengths of Cast Test Bars
As-Cast Diameter, in. (mm) Length, in. (mm)
Test Bar
Nominal Minimum Maximum
Minimum (Bottom) Maximum (Top)
(Mid-Length) (Specified) (Recommended)
A 0.88 (22.4) 0.85 (21.6) 0.96 (24.4) 5.0 (125) 6.0 (150)
B 1.20 (30.5) 1.14 (29.0) 1.32 (33.5) 6.0 (150) 9.0 (230)
C 2.00 (50.8) 1.90 (48.3) 2.10 (53.3) 7.0 (175) 10.0 (255)
A
S . . . . .
A
All dimensions of test bar S shall be as agreed upon by the manufacturer and the purchaser.
Tension Test Tension Test Tension Test
Dimensions, in. (mm)
Specimen A Specimen B Specimen C
G—Length of parallel, min 0.50 (13) 0.75 (19) 1.25 (32)
D—Diameter 0.500 6 0.010 0.750 6 0.015 1.25 6 0.025
(12.7 6 0.25) (19.1 6 0.4) (31.7 6 0.050)
R—Radius of fillet, min 1 (25) 1 (25) 2 (50)
1 1 1
A—Length of reduced section, min 1 ⁄4 (32) 1 ⁄2 (38) 2 ⁄4 (57)
3 3
L—Over-all length, min 3 ⁄4 (95) 4 (100) 6 ⁄8 (160)
7 1 7
C—Diameter of end section, approx ⁄8 (22.2) 1 ⁄4 (31.8) 1 ⁄8 (47)
1 1 5
E—Length of shoulder, min ⁄4 (6) ⁄4 (6) ⁄16 (8)
5 1 15 1 7 1
F—Diameter of shoulder ⁄8 6 ⁄64 ⁄16 6 ⁄64 1 ⁄16 6 ⁄64
(16 6 0.5) (25 6 0.5) (36 6 0.5)
AA A
B—Length of end section
A
Optiona
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