If you’re looking to find washers that match the one you have or get suitable washers for specific bolts in the USA, it’s imperative to be precise and know which you need. If you want washers that fit a given bolt, simply order washers with the same designation, for instance, M16 washers for M16 bolts. However, if you want washers similar to what you have, measure the interior diameter and order the size below that.
How to Get the Correct Washer Sizes
While tools like a measuring tape or ruler can do so, a vernier calliper is the best choice for accurate measurements.
The interior and exterior diameters are the most crucial measurements to establish which washer sizes you need.
Depending on the dimensions, your washer will likely fall within one of the three most popular washer measuring standards in the USA, as discussed below.
USS
USS washers are the largest and fit loosely. They’re popular for construction projects.
Here’s a chart showing standard USS flat washer sizes in the USA (inches):
| Nominal Size | Outside Diameter | Inside Diameter |
| 1/4 | 0.734 | 5/16 |
| 5/6 | 7/8 | 3/8 |
| 3/8 | 1 | 7/16 |
| 7/16 | 1-1/4 | 1/2 |
| 1/2 | 1-3/8 | 9/16 |
| 9/16 | 1-15/32 | 5/8 |
| 5/8 | 1-3/4 | 11/16 |
| 3/4 | 2 | 13/16 |
| 7/8 | 2-1/4 | 15/16 |
| 1 | 2-1/2 | 1-1/16 |
| 1-1/8 | 2-3/4 | 1-1/4 |
| 1-1/4 | 3 | 1-3/8 |
| 1-3/8 | 3-1/4 | 1-1/2 |
| 1-1/2 | 3-1/2 | 1-5/8 |
SAE
These are the most petite. They’re common in automotive applications and machinery that requires a tighter fit or where space is scarce.
Here’s a chart showing standard SAE flat washer sizes in the USA (inches):
| Nominal Size | Outside Diameter | Inside Diameter |
| #6 | 3/8 | 5/32 |
| #8 | 7/16 | 3/16 |
| #10 | 1/2 | 7/32 |
| #12 | 9/16 | 1/4 |
| 1/4 | 5/8 | 9/32 |
| 5/6 | 11/16 | 11/32 |
| 3/8 | 13/16 | 13/32 |
| 7/16 | 15/16 | 15/32 |
| 1/2 | 1-1/16 | 17/32 |
| 9/16 | 1-5/32 | 19/32 |
| 5/8 | 1-5/16 | 21/32 |
| 3/4 | 1-15/32 | 13/16 |
| 7/8 | 1-3/4 | 15/16 |
| 1 | 2 | 1-1/16 |
ASTM F436
These are slightly larger than SAE and come with the signature F436 branding. They often do the same tasks as SAE washers.
Get Washers of Any Size Today
Once you determine which washers you need, it’s time to source durable units. At Minneapolis Washer and Stamping, we offer long-lasting washers in numerous sizes and materials to suit customer needs all over the US. Shop with us now for durable, top-performing washers. Have questions? Contact us here or request a custom quote today.