• Fasteners for almost all your needs


  • TorqBolt provided Fastening Solutions with Desired Finish

  • Superior Washers for Better Fastening




ASTM A193

astm-a193-grade-B8-class-2-BoltsThis specification covers alloy steel and stainless steel bolting material for pressure vessels, valves, flanges, and fittings for high temperature or high pressure service, or other special purpose applications. Ferritic steels shall be properly heat treated as best suits the high temperature characteristics of each grade. Immediately after rolling or forging, the bolting material shall be allowed to cool to a temperature below the cooling transformation range. The chemical composition requirements for each alloy are presented in details.

 

B7 Alloy steel, AISI 4140/4142 quenched and tempered
B8 Class 1 Stainless steel, AISI 304, carbide solution treated.
B8M Class 1 Stainless steel, AISI 316, carbide solution treated.
B8 Class 2 Stainless steel, AISI 304, carbide solution treated, strain hardened
B8M Class 2 Stainless steel, AISI 316, carbide solution treated, strain hardened
B16 A heat-treated chromium-molybdenum-vanadium steel for high-pressure, high-temperature service.

 

Mechanical Properties
Bolt -Grade Identification Markings

Grade Size Tensile ksi, min Yield, ksi, min Elong, %, min RA % min
B7 Up to 2-1/2 125 105 16 50
2-5/8 - 4 115 95 16 50
4-1/8 - 7 100 75 18 50
B8 Class 1 All 75 30 30 50
B8M Class 1 All 75 30 30 50
B8 Class 2 Up to 3/4 125 100 12 35
7/8 - 1 115 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
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

 

Material Chemical Composition

Element B7 (AISI 4140) B8 (AISI 304) B8M (AISI 316)
Carbon 0.37 - 0.49% 0.08% max 0.08% max
Manganese 0.65 - 1.10% 2.00% max 2.00% max
Phosphorus, max 0.035% 0.045% 0.045%
Sulfur, max 0.040% 0.030% 0.030%
Silicon 0.15 - 0.35% 1.00% max 1.00% max
Chromium 0.75 - 1.20% 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%

 

Recommended Nuts,Bolts & Washer

Bolt Grade Nuts Washers
B7 A194 Grade 2H F436
B8 Class 1 A194 Grade 8 SS304
B8M Class 1 A194 Grade 8M SS316
B8 Class 2 A194 Grade 8 SS304
B8M Class 2 A194 Grade 8M SS316

 

Copyright © 2014 TorqBolt. All rights reserved. | Sitemap

Related Products:Bolts | Pipes | Flanges