ASTM F436 / F436M Hardened Steel Washers

ASTM F436 hardened steel washers are hardened washers specified for use with high-strength bolting and other structural or mechanical fasteners. The standard defines chemical, mechanical, and dimensional requirements and covers both inch and metric dimensions under ASTM F436/F436M. The product is commonly referred to as an ASTM F436 structural washer, hardened structural washer, or F436 washer in industrial purchasing.

The specification covers Type 1 carbon steel washers and Type 3 weathering steel washers. It also defines several washer styles, including circular washers for conventional bearing applications, beveled washers for structural members such as beams and channels, clipped washers for locations with limited clearance, and extra-thick circular washers for structural applications involving oversized holes. These distinctions are important when selecting a washer because the washer style is part of the product specification rather than simply a dimensional variation.

ASTM F436 washers are used with structural bolts, nuts, studs, and related threaded fasteners in steel construction, bridges, industrial equipment, infrastructure, and general heavy-duty mechanical assemblies. The standard covers nominal bolt sizes from 1/4 to 4 in. and M12 to M100. Metric and inch dimensions are treated as separate measurement systems under the standard, so buyers should specify the required system and nominal fastener size when ordering.