Flat Washers: The Size Charts Your Business Needs
Flat washers are instrumental fasteners for construction and machining jobs. This article explores the basic information you need to know about flat washers and includes a size chart so that you can choose the right flat washer for your application.
What Are Flat Washers?
Flat washers are the most common type of washer and are engineered to be flat, circular, and with a hole in the center. Generally, the role of a flat washer is to evenly distribute the load of a fastener—such as a screw or bolt—and provide a smooth surface to prevent damage to the substrate. Flat washers are available in a variety of sizes and thicknesses to complement their matching fasteners.
How to Choose the Right Size of Flat Washer for Your Application
The size of the flat washer you need depends on your application and the type of bolt being used. If you work in the U.S., your options will either conform to the standards of the Society of Automotive Engineers (SAE) or to the United States Standard (USS). It’s important to choose the right washer size because failure to do so may result in a faulty connection.
Flat Washer Size Charts
These charts can help you find the right size flat washer for your application.
| SAE Flat Washer Size Chart | |||
|---|---|---|---|
| Size | Inside Diameter | Outside Diameter | Thickness |
| #6 | 5/32" | 3/8" | 3/64" |
| #8 | 3/16" | 7/16" | 3/64" |
| #10 | 7/32" | 1/2" | 3/64" |
| 1/4" | 9/32" | 5/8" | 1/16" |
| 5/16" | 11/32" | 11/16" | 1/16" |
| 3/8" | 13/32" | 13/16" | 1/16" |
| 7/16" | 15/32" | 59/64" | 1/16" |
| 1/2" | 17/32" | 1-1/16" | 3/32" |
| 9/16" | 19/32" | 1-3/16" | 3/32" |
| 5/8" | 21/32" | 1-5/16" | 3/32" |
| 3/4" | 13/16" | 1-1/2" | 9/64" |
| 7/8" | 15/16" | 1-3/4" | 9/64" |
| 1" | 1-1/16" | 2" | 9/64" |
| 1-1/8" | 1-3/16″ | 2-1/4″ | 9/64″ |
| 1-1/4" | 1-5/16″ | 2-1/2″ | 5/32″ |
| 1-1/2" | 1-7/16″ | 3″ | 3/16″ |
| USS Flat Washer Size Chart | |||
|---|---|---|---|
| Size | Inside Diameter | Outside Diameter | Thickness |
| 3/16" | 1/4" | 9/16" | 3/64" |
| 1/4" | 5/16" | 3/4" | 1/16" |
| 5/16" | 3/8" | 7/8" | 5/64" |
| 3/8" | 7/16" | 1" | 5/64" |
| 7/16" | 1/2" | 1-1/4" | 5/64" |
| 1/2" | 9/16" | 1-3/8" | 7/64" |
| 9/16" | 5/8" | 1-1/2" | 7/64" |
| 5/8" | 11/16" | 1-3/4" | 9/64" |
| 3/4' | 13/16" | 2" | 5/32" |
| 7/8" | 15/16" | 2-1/4" | 11/64" |
| 1" | 1-1/16" | 2-1/2" | 11/64" |
| 1-1/8" | 1-1/4" | 2-3/4" | 11/64" |
| 1-1/4" | 1-3/8" | 3" | 11/64" |
| 1-3/8" | 1-1/2" | 3-1/4" | 3/16" |
| 1-1/2" | 1-5/8" | 3-1/2" | 3/16" |
| 1-5/8" | 1-3/4" | 3-3/4" | 3/16" |
| 1-3/4" | 1-7/8" | 4" | 3/16" |
| 1-7/8" | 2" | 4-1/4" | 3/16" |
| 2" | 2-1/8" | 4-1/2" | 3/16" |
| 2-1/2" | 2-5/8" | 5" | 15/64" |
| 3" | 3-1/8" | 5-1/2" | 9/32" |
Find Your Flat Washers at Zoro
Zoro has all the flat washers and fasteners your business needs. Shop today for everything your business needs at Zoro.
Product Compliance and Suitability
The statements contained in this guide are intended for general informational purposes only. Such statements do not constitute a product recommendation or representation as to the appropriateness, accuracy, completeness, correctness, or currentness of the information provided. Information provided in this guide does not replace the use by you of any manufacturer instructions, technical product manual, or other professional resource or adviser available to you. Always read, understand, and follow all manufacturer instructions.
