ASTM A193 Grade B8MNA Specification for high tensile bolts, screws, stud bolts, anchor bolts, threaded rods and other externally threaded fasteners, made from 316N stainless steel.

ASTM A193 Grade B8MNA is a standard material specification for high strength 316N 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 B8MNA is a carbide solution treated 316N stainless steel classified under tensile class 1A and having minimum tensile requirement of 75 ksi, yield 30 ksi and maximum hardness limit of 192 HBW or 90 HRB. This specification covers requirements for chemical composition, mechanical properties, hardness, heat-treatment and recommended nuts-washers for Grade B8MNA Fasteners.

Chemical Composition

Element	Nitrogen Enhanced Stainless Steel
	AISI 316N / UNS S31651
	CompositionA, %
Carbon	0.08 max
Manganese	2.00
Phosphorus	0.045 max
Sulfur	0.030 max
Silicon	1.00 max
Chromium	16.00 - 18.00
Nickel	10.00 - 13.00
Molybdenum	2.00 - 3.00
Nitrogen	0.10 - 0.16

^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 1A	All Sizes	80	35	30	40	223 HBW or 96 HRBB

Heat Treatment: Carbide Solution Treated in finished condition.