bolts

ASTM A193 Grade B8M Grade 1 Fasteners are similar to Grade B8 but are made of AISI 316 stainless steel instead of AISI 304 stainless steel. Type 316 stainless steel has better corrosion resistance than type 304 stainless steel due to the addition of molybdenum.

B8M Grade 1 fasteners require carbide solution treatment, while Grade 2 fasteners require additional strain hardening operations to increase strength and reduce susceptibility to wear.

ASTM A194 specification covers carbon, alloy and stainless steel nuts for high pressure and/or high temperature service. American National Standard Heavy Duty Hex Series (ANSI B 18.2.2) shall be used unless otherwise specified. Nuts no more than 1 inch in nominal size shall conform to UNC Series Class 2B.

Nuts with a nominal size over 1 inch shall be a UNC Series Class 2B fit or an 8 UN Series Class 2B fit. High strength ASTM A194 grade 2H nuts are common in the market and are often replaced by ASTM A563 grade DH nuts due to the limited availability of DH nuts in certain diameters and finishes.

ASTM A194 Class 2h bolts are carbon base steel heavy duty hex nuts. Sa194-2h material is a common high strength nut. This specification ASTM A194 Class 2h washers are typically used in conjunction with the following fastener standards – A193 Class B7, A325, A490.