5/8 Washer Dimensions & Size

5/8″ washers are commonly used with 5/8-inch bolts and nuts or screws in heavy construction, structural steel connections, industrial machinery, and mechanical assemblies. They are designed to distribute load, protect surfaces, and improve fastening stability under higher clamping forces. Under the USS standard, a 5/8″ plain washer typically has a nominal inner diameter of 11/16″ and a nominal outer diameter of 1-3/4″, with a thickness range of 0.108–0.160 inch. Under the SAE standard, it has a nominal inner diameter of 21/32″ and a nominal outer diameter of 1-5/16″, with a typical thickness range of 0.074–0.121 inch. All dimensions shown are based on USS and SAE standards.

Disclaimer: Washer dimensions and tolerances may vary by standard, manufacturer, material, or finish. Always confirm critical dimensions using the official product datasheet before installation.

Washer Diagram Anatomy
USS Standard
Dimensions Nominal Size (in) Actual Size (in)
Min Max
Inner Diameter 11/16 0.681 0.718
Outer Diameter 1-3/4 1.743 1.780
Thickness Not specified 0.108 0.160
SAE Standard
Dimensions Nominal Size (in) Actual Size (in)
Min Max
Inner Diameter 21/32 0.649 0.686
Outer Diameter 1-5/16 1.305 1.342
Thickness Not specified 0.074 0.121
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Frequently Asked Questions

What is the difference between USS and SAE washer standards?

USS (United States Standard) washers generally have a larger outer diameter and thicker profile, making them suitable for structural and heavy-duty applications. SAE (Society of Automotive Engineers) washers are typically smaller and thinner, designed for tighter tolerances and more compact assemblies.

What size is a 5/8″ washer?

The size of a 5/8″ washer depends on the standard. Under the USS standard, it typically has a nominal inner diameter of 11/16″ and a nominal outer diameter of 1-3/4″. Under the SAE standard, it usually has a nominal inner diameter of 21/32″ and a nominal outer diameter of 1-5/16″.

What is the inner diameter of a 5/8″ washer?

The inner diameter is larger than the bolt size to allow clearance. It is typically 11/16″ for USS washers and 21/32″ for SAE washers.

What is the outer diameter of a 5/8″ washer?

The outer diameter varies by standard, with 1-3/4″ for USS washers and 1-5/16″ for SAE washers.

How thick is a 5/8″ washer?

Washer thickness varies by standard and manufacturer. Typically, USS 5/8″ washers range from 0.108 to 0.160 inch, while SAE 5/8″ washers range from 0.074 to 0.121 inch.