The ASTM F2281 standard specifies the chemical and mechanical requirements for stainless steel and nickel alloy bolts, hex cap screws, and studs with a diameter of 1/4 inch or larger that are intended for use at temperatures up to 1800°F (982°C) and in applications where heat resistance and high temperature effects are critical. Due to unique alloy properties, this standard covers a wide range of materials that may be employed at high temperatures, as well as environmental requirements such as corrosive situations. The specifications A276, A484/A484M, A493, A564/A564M, A582/A582M, and B637 are only given here as possible material sources for producing bolts, hex cap screws, and studs to this specification.
| Alloy | C | Mn | P | S | Si | Cr | Ni | Cu | Mo | Other |
|---|---|---|---|---|---|---|---|---|---|---|
| ASTM F2281 660 Type III, Class B | 0.08 | 2.00 | 0.040 | 0.030 | 1.00 | 13.5-16.0 | 24.0-27.0 | . . . | 1.00-1.75 | Ti 1.90-2.30 V 0.10-0.50 Al 0.35 max B 0.003-0.010 Fe remainder |
| Alloy Grades | Condition | Marking | Nominal Diameter, in. | Full-Size Tests | Rockwell Hardness | Machined Specimen Tests | |||
|---|---|---|---|---|---|---|---|---|---|
| Tensile Strength, min, ksi | Yield Strength, min, ksi | Tensile Strength, min, ksi | Yield Strength, min, ksi | Elongation 4D, min % | |||||
| ASTM F2281 660 Type III, Class B | Ah4 | F3D | All diameters | 130 | 85 | 22 to 37 HRC | 130 | 85 | 15 |
| Ah4 | F3E | All diameters | 130 | 85 | 22 to 37 HRC | 130 | 85 | 15 | |
| Ah4 | F3F | All diameters | 130 | 85 | 22 to 37 HRC | 130 | 85 | 15 | |