Frequently Asked Question
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
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
Examples of castings often made to ASTM A47 that Portland Bolt stocks include:
ASTM A48
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
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:
- Hillside Washers (Grade 65-45-12), although some are made to ASTM A48.
