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Gray Iron has a dense gray structure and offers excellent machinability.
Grades 25, 30, 35 and 40 can fill specific requirements for hardness and wear, and heat treatments can yield even higher mechanical properties. Popular applications for gray iron include diesel and gasoline engine blocks and cylinder liners, and structural machine components where vibration dampening is required.
Specifying Body |
Spec. No. |
Use |
Grade or Class |
Min. Tensile Strength (PSI) |
Other Requirements |
ASTM |
A126 |
Valves, flanges and pipe fittings |
A |
21000 |
.15% S. Max. .75% P Max |
B |
31000 |
C |
41000 |
ASTM |
A48 |
Castings intended for general engineering use where strength is a major consideration |
25 |
25000 |
1. Test bar size shall be related in cooling to the critical section of the casting and so specified.
2. At least two test bars shall be cast and prepared for each casting lot, the lot size being designated.
3. Test bars shall be cast in dry silica sand molds similar to that in which the castings are poured.
4. Tension tests shall be under true axial loading. |
30
35 |
30000
35000 |
40 |
40000 |
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Brinell Hardness |
Micro-structure |
ASTM
SAE |
A159
J431 |
Cast in sand molds for the automobile, truck, tractor, and allied industries |
G2500 |
|
170-229 |
Ferritic-Pearlitic |
G3000 |
187-241 |
Pearlitic |
G3500 |
207-255 |
Pearlitic |
G4000 |
217-269 |
Pearlitic |
ASTM |
A278 |
Pressure containing parts for use up to 650ºF |
25 |
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Castings for intended use above 450ºF should be stress relieved. |
30 |
35 |
(This article is taken from an American Foundry's website: BENTON FOUNDRY, INC.) |
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