Structural Washers

What are Structural Washers?

Structural washers are heavy duty flat washers made from hardened steel for high strength bolted connections. They are thicker than standard flat washers and are used with structural bolts to spread load and protect bearing surfaces in critical joints.

What do structural washers do?

• Distribute clamp force under large hex structural nuts and bolt heads
• Reduce pull-through and surface crushing on steel plates and members
• Support consistent preload in slip critical, bearing type, and tensioned joints

When should I use structural washers?

Use structural washers where drawings or codes call for hardened washers in structural steel connections, base plates, and framing. They are selected when predictable clamp load and durable seating are required.

Structural washer vs standard flat or fender washer what is the difference?

A standard flat washer is thinner for general load spread. A fender washer has a very large outside diameter for coverage but is not intended for high strength joints. A structural washer is hardened and thicker to handle the high loads of structural bolt assemblies.

What size structural washer do I need inch and metric

• Select by bolt size such as 1/2 in, 5/8 in, 3/4 in, 7/8 in, or 1 in, or metric sizes such as M12, M16, M20, and M24
• Confirm the inner diameter fits the bolt shank and that the outside diameter covers the hole with proper margin
• Follow project specifications for washer thickness and placement within the assembly

Material and specification details

F436 plain alloy steel

Hardened alloy steel washer for structural use that provides strength and wear resistance under high clamp loads. Plain finish is suitable for shop fabricated or otherwise protected conditions when a coating is not specified.

Installation tips

• Place washers where specified in the bolt assembly and ensure clean, flat bearing surfaces
• Tighten using the method required for the structural bolt assembly and verify tension as specified
• Re check after fit up and alignment to ensure even seating on the plate

Applications

• Structural steel framing, columns, and beams
• Base plates, anchor rod connections, and bracing
• Industrial fabrications where hardened seating is required