Nut and Bolt Size Chart
Match bolt diameter to the nut across the flats, wrench size, and washer outside diameter.
| Bolt size | Nut across flats (in) | Wrench size (in) | Washer OD — USS (in) |
|---|---|---|---|
| 1/4 | 7/16 | 7/16 | 5/8 |
| 5/16 | 1/2 | 1/2 | 3/4 |
| 3/8 | 9/16 | 9/16 | 13/16 |
| 7/16 | 11/16 | 11/16 | 1 |
| 1/2 | 3/4 | 3/4 | 1-1/16 |
| 5/8 | 15/16 | 15/16 | 1-3/8 |
| 3/4 | 1-1/8 | 1-1/8 | 1-5/8 |
SAE finished hex nut and USS washer dimensions. Heavy hex nuts run larger.
Printable PDF
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