ASTM A193 BOLT MANUFACTURER, SUPPLIERS & STOCKIST
ASTM A193 Bolts Specifications
ASTM A193 Bolt Specifications
Originally approved in 1936, this specification is heavily utilized in petroleum and chemical construction applications. The ASTM standard covers alloy steel and stainless steel bolting materials for high temperature or high pressure service. This specification includes fasteners intended for use in pressure vessels, valves, flanges, and fittings. Although, this material is often available in national coarse (UNC) thread pitches, if being used in traditional applications, threads are specified 8 threads per inch (tpi) for diameters above one inch.
Below is a basic summary of a few of the common grades. ASTM A193 covers a number of other standard specifications not covered in this description including B5, B6, and B16.
ASTM A193 Grades Bolts :
| ASTM A193 Grade B7 | Alloy steel, AISI 4140/4142 quenched and tempered |
| ASTM A193 Grade B8 | Class 1 Stainless steel, AISI 304, carbide solution treated. |
| ASTM A193 Grade B8M | Class 1 Stainless steel, AISI 316, carbide solution treated. |
| ASTM A193 Grade B8 | Class 2 Stainless steel, AISI 304, carbide solution treated, strain hardened |
| ASTM A193 Grade B8M | Class 2 Stainless steel, AISI 316, carbide solution treated, strain hardened |
ASTM A193 Mechanical Properties of Bolts :
| Grade | Size | Tensile ksi, min | Yield, ksi, min | Elong, %, min | RA % min | HBW | HRC |
| B7 | Up to 2-1/2 | 125 | 105 | 16 | 50 | 321 max | 35 max |
| 2-5/8 - 4 | 115 | 95 | 16 | 50 | |||
| 4-1/8 - 7 | 100 | 75 | 18 | 50 | |||
| B8 Class 1 | All | 75 | 30 | 30 | 50 | 223 max | 35 max |
| B8M Class 1 | All | 75 | 30 | 30 | 50 | 223 max | 96 max |
| B8 Class 2 | Up to 3/4 | 125 | 100 | 12 | 35 | 321 max | 35 max |
| 37110 | 115 | 80 | 15 | 35 | |||
| 1-1/8 - 1-1/4 | 105 | 65 | 20 | 35 | |||
| 1-3/8 - 1-1/2 | 100 | 50 | 28 | 45 | |||
| B8M Class 2 | Up to 3/4 | 110 | 95 | 15 | 45 | 321 max | 35 max |
| 7/8 -1 | 100 | 80 | 20 | 45 | |||
| 1-1/8 - 1-1/4 | 95 | 65 | 25 | 45 | |||
| 1-3/8 - 1-1/2 | 90 | 50 | 30 | 45 |
ASTM A193 Chemical Properties of Bolts:
| Element | B7 (AISI 4140) | B8 (AISI 304) | B8M (AISI 316) |
| Carbon | 0.38 - 0.48% | 0.08% max | 0.08% max |
| Manganese | 0.75 - 1.00% | 2.00% max | 2.00% max |
| Phosphorus, max | 0.00035 | 0.00045 | 0.00045 |
| Sulfur, max | 0.0004 | 0.0003 | 0.0003 |
| Silicon | 0.15 - 0.35% | 1.00% max | 1.00% max |
| Chromium | 0.80 - 1.10% | 18.0 - 20.0% | 16.0 - 18.0% |
| Nickel | 8.0 - 11.0% | 10.0 - 14.0% | |
| Molybdenum | 0.15 - 0.25% | 2.00 - 3.00% |