Structural F436 Plain Alloy Flat Washers

What is the ASTM F436 washer spec?

F436 is a mechanical performance specification, not a dimensional pattern, that calls for a hardened, heat-treated washer able to withstand the high clamping loads of structural bolting such as A325 and A490. The hardness keeps the washer from crushing or dishing under the bolt, which preserves preload and joint integrity in steel-to-steel connections. A washer can be F436-rated in a USS-style dimension, combining structural hardness with a wide bearing footprint. Use F436 washers wherever structural bolts require a hardened washer under the head or nut.

Why choose F436 structural flat washers

• Structural grade: meets ASTM F436 for hardened performance.
• Resists deformation: hardened to hold up under structural bolt loads.
• Preserves preload: keeps clamping force in steel connections.
• Construction standard: pairs with A325 and A490 structural bolts.

Common applications for F436 flat washers

• Structural steel connections
• Bridges, buildings, and heavy frames
• A325 and A490 bolted joints
• High-load construction fastening

For general and hardened washer options, browse every type on the main flat washers category, or see the F436 plain alloy flat washers range.

Structural F436 Flat Washers FAQ

What is ASTM F436?

F436 is a specification for hardened, heat-treated washers used with high-strength structural bolts, ensuring they resist deformation under high clamping loads.

Is F436 a size or a strength rating?

It is a mechanical performance rating, not a dimensional pattern. An F436 washer can come in USS-style dimensions while meeting the hardness requirement.

What bolts use F436 washers?

High-strength structural bolts such as A325 and A490 in steel construction call for hardened F436 washers.