ASTM A193 Grade B8CA is a standard material specification for corrosion resistant grade 347 stainless steel fasteners such as hex bolts, screws, stud bolts, 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 B8CA is similar to B8C but the latter is carbide solution treated after head formig and the former is carbide solution treated in finished condition. Grade B8CA is classified under tensile Class 1A and has a lower hardness requirement compared to B8C. This specification covers requirements for chemical composition, mechanical properties, hardness, heat-treatment and recommended nuts-washers for Grade B8CA Fasteners.
| Element | Austenitic Stainless Steel |
|---|---|
| AISI 347 | |
| CompositionA, % | |
| Carbon | 0.08 max |
| Manganese | 2.00 |
| Phosphorus | 0.045 max |
| Sulfur | 0.030 max |
| Silicon | 1.00 max |
| Chromium | 17.00 - 19.00 |
| Nickel | 9.00 - 12.00 |
| Columbium + tantalum | 10 x Carbon Content - 1.10 |
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 1A | All Sizes | 75 | 30 | 30 | 50 | 192 HBW or 90 HRB |
Heat Treatment: Carbide Solution Treated in finished condition.
| Nut Specification | Washer Specification |
|---|---|
| ASTM A194 Grade 8CA | ASTM A240 TP347 |
| Commonly Produced B8CA 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 |