ASTM A193 Grade B8SA is a standard material specification for high strengt, corrosion resistant Alloy 218 / UNS S21800 / Nitronic 60 stainless steel fasteners such as bolts, screws, studs, threaded rods and other externally threaded parts, for use in high tensile, high temperature and special purpose applications such as pressure piping & pressure vessels bolting. Grade B8SA is a carbide solution treated stainless steel classified under Class 1C, having minimum tensile requirement of 95 ksi, yield 50 ksi and maximum hardness limit of 271 HBW or 28 HRC. This specification covers requirements for chemical composition, mechanical properties, hardness, heat-treatment and recommended nuts-washers for Grade B8SA Fasteners.
| Element | Austenitic Stainless Steel |
|---|---|
| Alloy 218 / UNS S21800 / Nitronic 60 | |
| CompositionA, % | |
| Carbon | 0.10 max |
| Manganese | 7.00 - 9.00 |
| Phosphorus | 0.060 max |
| Sulfur | 0.030 max |
| Silicon | 3.50 - 4.50 |
| Chromium | 16.00 - 18.00 |
| Nickel | 8.00 - 9.00 |
| Nitrogen | 0.08 - 0.18 |
AThe intentional addition of Bi, Se, Te, and Pb is not permitted.
| Tensile Class | Diameter, Inch | Tensile Strength, min, ksi |
Yield Strength, min, 0.2% offset, ksi |
Elongation in 4D, min, % |
Reduction of Area, min, % |
Hardness, max |
|
|---|---|---|---|---|---|---|---|
| Class 1C | All Sizes | 95 | 50 | 35 | 55 | 271 HBW or 28 HRC | |
Heat Treatment: Carbide Solution Treated
| Nut Specification | Washer Specification |
|---|---|
| ASTM A194 Grade 8S | ASTM A240 UNS S21800 |
| Commonly Produced B8SA Fasteners | ||||
|---|---|---|---|---|
| Hex Bolts | Heavy Hex Bolts | Stud Bolts | Threaded Rods | Anchor Bolts |
| Eye Bolts | Socket Head Cap Screws | Countersunk Screws | U Bolts | Square Head Bolts |