In high-strength structural bolting, standard commercial washers are simply not hard enough. Under the enormous preload forces generated by Grade 8.8, 10.9, and 12.9 bolts, standard washers can buckle, extrude, or compress excessively, causing significant loss of clamp load in the joint. JLHY's hardened structural washers are specifically designed to handle these extreme loads without deforming.

Structural washers — also called rigid plate washers or ASTM F436 washers — are manufactured from heat-treated carbon steel to achieve surface and core hardness values (HRC 38-45) that resist indentation from bolt head/nut bearing edges and prevent yielding under high compressive stresses.

JLHY's hardened structural washers comply with EN 14399-1 (for HR washers) and ASTM F436 specifications. They are manufactured with precise thickness tolerances to ensure consistent performance in preloaded structural connections. Tight thickness control prevents the washer from being drawn into thread roots under high preload.

These washers are an essential component in any structural bolting system using high-strength structural bolts. JLHY supplies hardened washers to structural steel fabricators, bridge contractors, and engineering firms worldwide. Full traceability documentation is available for every batch.

Contact our structural engineering support team to specify the correct hardened washer for your bolt grade and connection design.