ASTM A193 Grade B8TA is a standard material specification for corrosion resistant 321 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 B8TA is a carbide solution treated 321 stainless steel and similar to B8T except that the latter is carbide solution treated after head forming and the former is carbide solution treated in finished condition. Grade B8TA is classified under tensile class 1A haveing minimum tensile requirement of 75 ksi, yield 30 ksi and maximum hardness limit of 192 HBW or 90 HRB. This specification covers requirements for chemical composition, mechanical properties, hardness, heat-treatment and recommended nuts-washers for Grade B8TA Fasteners.
| Element | Austenitic Stainless Steel |
|---|---|
| AISI 321 / 321H | |
| 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 |
| Titanium | 5 x Carbon Content - 0.70 |
| Nitrogen | 0.10 max |
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 1 | 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 8TA | ASTM A240 TP321 |
| Commonly Produced B8TA 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 |