The ASTM A193 specification comprises various grades, each defined by its own distinct chemical composition, mechanical strength, and testing protocols. While this site provides a helpful overview of how these grades compare, you should consult the official ASTM International documentation for the definitive technical standards and requirements.
Nuts
Nuts used with ASTM A193 bolts must meet the ASTM A194 specification. Since A194 includes various grades, the correct selection depends on the chemical composition and strength of the specific bolt being used. To ensure a proper fit, these nuts feature a heavy hex pattern, matching the bolt head’s width across the flats. The following chart details the compatible bolt-and-nut pairings.
Heavy Hex Nut Dimensions
Washers
ASTM F436 hardened washers are designed for use with A193 Grade B7, B7M, and B16 bolts. Note that washer dimensions may differ when paired with stainless steel grades.
