Metric Class 10.9 Zinc Plated Steel Flat Washers

Why use a Class 10.9 washer?

High-strength Class 10.9 metric bolts generate high clamping force that can dent or dish an ordinary washer, which loses preload and weakens the joint. A hardened Class 10.9 washer resists that deformation, spreading the load properly under the bolt head or nut so the connection holds tension. Match the washer class to the bolt, since pairing a hardened washer with a hardened bolt keeps the whole joint balanced. The zinc plating adds corrosion resistance for indoor and general outdoor use.

Why choose Class 10.9 zinc plated flat washers

• High strength: hardened to resist deformation under Class 10.9 bolts.
• Preserves preload: will not dish and lose clamping force.
• Metric sizing: matched to high-strength metric bolts.
• Zinc plated: added corrosion resistance for general use.

Common applications for Class 10.9 flat washers

• High-strength metric bolted joints
• Machinery and structural connections
• Automotive and heavy equipment
• Any joint using Class 10.9 bolts

For standard-strength metric washers, see metric zinc plated flat washers, and browse every material on the main flat washers category.

Class 10.9 Zinc Plated Flat Washers FAQ

What does Class 10.9 mean on a washer?

It indicates a hardened, high-strength washer matched to Class 10.9 metric bolts, able to resist the high clamping load without deforming.

Why not use a standard washer under a Class 10.9 bolt?

A standard washer can dish or dent under the high clamping force, losing preload and weakening the joint. A hardened washer holds up.

Are these good outdoors?

The zinc plating suits indoor and general dry outdoor use. For wet or coastal exposure, a stainless option resists corrosion better.