ASTM F436 FLAT WASHER:

ASTM F436 FLAT WASHER covers the chemical and mechanical requirements for hardened washers in diameters. It is ranging from 1/4″ to 4″ inclusive. Meanwhile These heat treated washers are for general purpose and structural use and are suitable for use with A325 and A490 structural bolts. F436 Material Grade are hardened flat washers which have a Rockwell Hardness value ranging between 38 to 45 HRC. These washers can either have a plain finish or can be hot dipped galvanized. The hardened flat F436 Washer is used under bolt nuts and head in order to increase the bearing area.

General:

Moreover Structural washers are thick, strong washers used in heavy-duty building construction. For outside building applications, structural washers are typically coated or galvanized for corrosion resistance. Flat washers are used to increase the bearing surface of a nut or fastener’s head. Thus spreading the clamping force over a larger area. Washer size refers to its nominal hole size and is based on screw size. Its outside diameter (OD) is always larger. F436 washers are Hardened washers are made physically stronger through hardening or carburizing. But are generally smaller in size than your standard washer. Hardened flat washers are designed with extra strength and can be used with Grade 8 bolts and other heat-treated fasteners.