ASTM A193 Grade B8M Bolts, Stud Bolts, Fasteners

Standard Specification for Alloy-Steel and Stainless Steel Bolting for High Temperature or High Pressure Service and Other Special Purpose Applications

ASTM A193 specification covers alloy and stainless steel bolting for pressure vessels, valves, flanges, and fittings for high temperature or high pressure service, or other special purpose applications. Several grades are covered, including ferritic steels and austenitic stainless steels designated B5, B6, B7, B8, B8M, etc. Selection will depend upon design, service conditions, mechanical properties, and high temperature characteristics. This specification is expressed in both inch-pound units and in SI units; however, unless the purchase order or contract specifies the applicable A193M specification designation (SI units), the inch-pound units shall apply

ASTM A193 Grade B8M

Grade Tensile Class Raw Material Description
B8M Class 1 AISI 316 Stainless Steel, Carbide Solution Treated
B8M Class 2 AISI 316 Stainless Steel, Carbide Solution Treated and Strain Hardened

ASTM A193 Grade B8M Properties

ASTM A193 Grade B8M Chemical Composition

Carbon, max Manganese, max Phosphorus, max Sulfur, max Silicon, max Chromium Molybdenum
0.08 2.00 0.045 0.030 1.00 16.0 - 18.0 2.00 - 3.00

ASTM A193 Grade B8M Mechanical Properties

Grade Diameter Tensile Strength Yield Strength Elongation Reduction Hardness
Grade B8, B8M, Class 1, 1D All Diameters 515 205 30 50 223 HBW or 96 HRB
Grade B8M, B8MLCuN, Class 2 M20 and under 760 655 15 45 321 HBW or 35 HRC
Grade B8M, B8MLCuN, Class 2 M20 to M24, inclusive 690 550 20 45 321 HBW or 35 HRC
Grade B8M, B8MLCuN, Class 2 M24 to M30, inclusive 655 450 25 45 321 HBW or 35 HRC
Grade B8M, B8MLCuN, Class 2 M30 to M36, inclusive 620 345 30 45 321 HBW or 35 HRC

ASTM A193 Grade B8M Bolt Marking

Class Manufacturer's Mark Grade Symbol
Class 1 BPF B8M
Class 1B BPF B8Y or B8MN
Class 1D BPF B95
Class 2 BPF B8MSH

Recommended Nuts & Washers

Bolting Grade Nut Grade Washer Grade
ASTM A193 Grade B8M, B8MA, B8M2, B8M3 ASTM A194 Grade 8M, 8MA SS 316

ASTM A193 Grade B8M Bolting

Hex Bolt Heavy Hex Bolts Stud Bolts Threaded Rods Anchor Bolts
Eye Bolts Socket Head Cap Screws Countersunk Screws J Bolts Square Head Bolts