USS Flat Washers

USS vs SAE flat washers

USS and SAE are two dimensional patterns, and the difference is size. For a given inside diameter, a USS washer has a larger outer diameter and thicker body than an SAE washer, so it spreads load over more surface. That makes USS the choice for construction, steel structures, and larger fasteners where broad load distribution and stability matter, while SAE, with its smaller footprint, suits automotive and tight-clearance work. Choose USS for a wider bearing surface, then choose the finish or grade for the environment and load, from economical zinc to thru-hardened Grade 8 for high-strength joints.

Finish and grade choices for USS washers

• Zinc plated: economical corrosion resistance for indoor and dry use.
• Hot dipped galvanized: heavier zinc coating for outdoor and wet use.
• Grade 8 thru-hardened: high-strength washers for high-load bolts.
• Black chrome: dark decorative finish for visible hardware.

Common applications for USS flat washers

• Construction and steel structures
• Larger fasteners needing wide bearing
• Heavy equipment and machinery
• Outdoor structural work (galvanized)

For a smaller, tighter pattern, see SAE flat washers, and browse every option on the main flat washers category.

USS Flat Washers FAQ

What is the difference between USS and SAE washers?

For a given bolt, a USS washer has a larger outer diameter and thicker body than an SAE washer, giving a wider bearing surface for heavier load distribution.

When should I use a USS washer?

Use USS for construction, steel structures, and larger fasteners where you want to spread load over a broad surface. SAE suits automotive and tight-clearance work.

Do USS washers have a strength grade?

Plain USS washers are a dimensional pattern without a defined grade. For high-strength joints, choose a thru-hardened Grade 8 USS washer.