U.S. Bolts - Head and Wrench Sizes
Hex Bolt, Lag Bolt, Square Bolt and Heavy Hex Bolt.
Head and wrench size U.S. bolts:
| Bolt Diameter (in) | Head and Wrench Size (in) | |
|---|---|---|
| Hex Bolt Lag Bolt Square Bolt | Heavy Hex Bolt | |
| #6 | 1/4 | |
| #8 | 1/4 | |
| #10 | 5/16 | |
| #12 | 5/16 | |
| 1/4 | 7/16 or 3/8 | |
| 5/16 | 1/2 | |
| 3/8 | 9/16 | |
| 7/16 | 5/8 | |
| 1/2 | 3/4 | 7/8 |
| 9/16 | 13/16 | |
| 5/8 | 15/16 | 1 1/16 |
| 3/4 | 1 1/8 | 1 1/4 |
| 7/8 | 1 5/16 | 1 7/16 |
| 1 | 1 1/2 | 1 5/8 |
| 1 1/8 | 1 11/16 | 1 -3/4 |
| 1 1/4 | 1 7/8 | 2 |
| 1 3/8 | 2 1/16 | |
| 1 1/2 | 2 1/4 | |
- 1 in = 25.4 mm
- ANSI/ASME B18.2.1 Square, Hex, Heavy Hex, and Askew Head Bolts and Hex, Heavy Hex, Hex Flange, Lobed Head, and Lag Screws (Inch Series)
