ASTM A193 Grade B8M3 Specification for high tensile bolts, screws, stud bolts, anchor bolts, threaded rods and other threaded fasteners, made from 316 stainless steel.

ASTM A193 Grade B8M3 is a standard material specification for high strength, corrosion resistant 316 stainless steel fasteners such as bolts, screws, studs, threaded rods and other externally threaded parts, for use in high tensile, high temperature and special purpose applications such as pressure piping & pressure vessels bolting. Grade B8M3 is a carbide solution treated & strain hardened stainless steel classified under class 2C and both having a minimum tensile requirement of 85 ksi, yield 60 ksi and maximum hardness limit of 321 HBW or 35 HRC. This specification covers requirements for chemical composition, mechanical properties, hardness, heat-treatment and recommended nuts-washers for Grade B8M3 Fasteners.

Chemical Composition

Element	Austenitic Stainless Steel
	AISI 316 / 316L
	CompositionA, %
Carbon	0.08 max
Manganese	2.00 max
Phosphorus	0.045 max
Sulfur	0.030 max
Silicon	1.00 max
Chromium	16.00 - 18.00
Nickel	10.00 - 14.00
Molybdenum	2.00 - 3.00

^AThe intentional addition of Bi, Se, Te, and Pb is not permitted.

Mechanical Properties

Tensile Class	Diameter, Inch	Tensile Strength, min, ksi	Yield Strength, min, 0.2% offset, ksi	Elongation in 4D, min, %	Reduction of Area, min, %	Hardness, max
								Class 2CA	2 and under	85	65	30	60	321 HBW or 35 HRC
						over 2 inclusive	85		60	30	60

Heat Treatment: Carbide Solution Treated and Strain Hardened
A: For diameters 11⁄2 and over, center (core) properties may be lower than indicated by test reports which are based on values determined at 1⁄2 radius.