What is the difference between ASTM A47, A48, and A536?

ASTM A47, A48, and A536 are all casting specifications. Each grade has its own strength requirements and base material used. Each grade is also commonly associated with a particular finished part that Portland Bolt stocks.


ASTM A47 covers ferritic malleable castings intended for general use at temperatures from normal ambient to approximately 750° F. A47 castings are limited to one available grade: Grade 32510 for imperial castings, Grade 22010 for metric castings.

A47 Mechanical Properties

Grade Tensile, min Yield, min Elongation, min% Hardness, typical
32510 (English) 50,000psi 32,500psi 10 in 2” 156 HBN
22010 (Metric) 340MPa 220MPa 10 in 50mm 156 HBN

A47 Casting Examples

Malleable Iron Washer
Examples of castings often made to ASTM A47 that Portland Bolt stocks include:


ASTM A48 covers gray iron castings intended for general use. A48 castings are supplied based solely on tensile strength where no chemical requirements or ductility is specified. The tensile strength requirements are specified by class number and class type. Example: casting would be specified as A48-30A

Class Number Tensile Strength, ksi min
20 20
25 25
30 30
35 35
40 40
45 45
50 50
55 55
60 60
Class Type Nominal Test Bar Diameter, inches
A 0.88
B 1.2
C 2
S Agreed on between manufacturer and purchaser

A48 Casting Examples

Examples of castings often made to ASTM A48 that Portland Bolt stocks include:


ASTM A536 covers castings made of ductile iron, also known as spheroidal or nodular iron.  A536 has mechanical property requirements for both general use castings as well as special application castings. Examples of special applications include pipes, fittings, etc.

A536 Mechanical Properties for General Purpose Castings

Grade 60-40-18 Grade 65-45-12 Grade 80-55-06 Grade 100-70-03 Grade 120-90-02
Tensile, ksi min 60 65 80 100 120
Yield, ksi min 40 45 55 70 90
Elong, 2% min 18 12 6 3 2

A536 Mechanical Properties for Special Application Castings

Grade 60-42-10 Grade 70-50-05 Grade 80-60-03
Tensile, ksi min 60 70 80
Yield, ksi min 42 50 60
Elong, 2% min 10 5 3

A536 Casting Examples

Examples of castings often made to ASTM A536 that Portland Bolt stocks include:

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