ASTM A193 Grade B8 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 B8 Raw Material

Grade Tensile Class Raw Material Description
B8 Class 1 AISI 304 Stainless Steel, Carbide Solution Treated
B8 Class 2 AISI 304 Stainless Steel, Carbide Solution Treated and Strain Hardened

ASTM A193 Grade B8 Properties

ASTM A193 Grade B8 Chemical Composition

Carbon Manganese, max Phosphorus, max Sulfur, max Silicon Chromium
0.08 2.00 0.045 0.030 1.00 18.0-20.0

ASTM A193 Grade B8 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 B8, B8C, B8T, Class 2 M20 and under 860 690 12 35 321 HBW or 35 HRC
Grade B8, B8C, B8T, Class 2 M20 to M24, inclusive 690 550 20 45 321 HBW or 35 HRC
Grade B8, B8C, B8T, Class 2 M24 to M30, inclusive 655 450 25 45 321 HBW or 35 HRC
Grade B8, B8C, B8T, Class 2 M30 to M36, inclusive 620 345 30 45 321 HBW or 35 HRC
Grade B8, B8M2, Class 2B M48 and under 655 515 25 40 321 HBW or 35 HRC
Grade B8, B8M2, Class 2B M48 to M64, inclusive 620 450 30 40 321 HBW or 35 HRC
Grade B8, B8M2, Class 2B M64 to M72, inclusive 550 380 30 40 321 HBW or 35 HRC

Heat Treatment

ASTM A193 Grade B8 Bolt Marking

Class Manufacturer's Mark Grade Symbol
Class 1 BPF B8
Class 1D BPF B94
Class 2 BPF B8SH
Class 2B BPF B9

Recommended Nuts & Washers

Bolting Grade Nut Grade Washer Grade
ASTM A193 Grade B8 ASTM A194 Grade 8 SS 304

ASTM A193 Grade B8 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