ASTM A193 Grade B8SA Specification for high tensile bolts, screws, stud bolts, anchor bolts, threaded rods and other threaded fasteners, made from Alloy 218 / UNS S21800 / Nitronic 60 stainless steel.

ASTM A193 Grade B8SA is a standard material specification for high strengt, corrosion resistant Alloy 218 / UNS S21800 / Nitronic 60 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 B8SA is a carbide solution treated stainless steel classified under Class 1C, having minimum tensile requirement of 95 ksi, yield 50 ksi and maximum hardness limit of 271 HBW or 28 HRC. This specification covers requirements for chemical composition, mechanical properties, hardness, heat-treatment and recommended nuts-washers for Grade B8SA Fasteners.

Chemical Composition

Element	Austenitic Stainless Steel
	Alloy 218 / UNS S21800 / Nitronic 60
	CompositionA, %
Carbon	0.10 max
Manganese	7.00 - 9.00
Phosphorus	0.060 max
Sulfur	0.030 max
Silicon	3.50 - 4.50
Chromium	16.00 - 18.00
Nickel	8.00 - 9.00
Nitrogen	0.08 - 0.18

^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 1C	All Sizes	95	50	35	55	271 HBW or 28 HRC

Heat Treatment: Carbide Solution Treated