ASTM A193 Grade B8MLCuNA 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

Bolting Grade B8MLCuNA

Grade Tensile Class Raw Material Description
B8MLCuNA UNS S31254 Stainless Steel, Carbide Solution Treated

ASTM A193 Grade B8MLCuNA Chemical Composition

Austenitic Steels, Classes 1A, 1B, 1D, and 2
Element Grade B8MLCuNA
Carbon
Manganese, max
Phosphorus, max
Sulfur, max
Silicon
Chromium
Molybdenum
Columnium + Tantalum

ASTM A193 Grade B8MLCuNA Mechanical Properties

The material as represented by the tension specimens shall conform to the requirements at room temperature after heat treatment. Alternatively, stainless strain hardened fasteners (Class 2, 2B, and 2C) shall be tested full size after strain hardening to determine tensile strength and yield strength and shall conform to the requirements prescribed in Table 2 and 3. Should the results of full size tests conflict with results of tension specimen tests, full size test results shall prevail.

Grade Diameter Tensile Strength Yield Strength Elongation Reduction Hardness
Grade B8MLCuNA, Class 1A All Diameters 515 205 30 50 192 HBW or 90 HRB

ASTM A193 Grade B8MLCuNA Marking Requirements

Class Grade Grade Symbol
Class 1A B8MLCuNA B9K or B8MLCuNA

Recommended Nuts & Washers

Bolting Grade Nut Grade Washer Grade
ASTM A193 Grade B8MLCuNA ASTM A194 Grade 8MLCuNA 254SMO / UNS S31254