Square Head Dimensions
| Bolt Diameter | D | F | C | H | |||||
|---|---|---|---|---|---|---|---|---|---|
| Body Diameter | Width Across Flats | Width Across Corners | Height | ||||||
| Max | Basic | Max | Min | Max | Min | Basic | Max | Min | |
| 1⁄2 | 0.515 | 3⁄4 | 0.750 | 0.725 | 1.061 | 0.995 | 21⁄64 | 0.348 | 0.308 |
| 5⁄8 | 0.642 | 15⁄16 | 0.938 | 0.906 | 1.326 | 1.244 | 27⁄64 | 0.444 | 0.400 |
| 3⁄4 | 0.768 | 11⁄8 | 1.125 | 1.088 | 1.591 | 1.494 | 1⁄2 | 0.524 | 0.476 |
| 7⁄8 | 0.895 | 15⁄16 | 1.312 | 1.269 | 1.856 | 1.742 | 19⁄32 | 0.620 | 0.568 |
| 1 | 1.022 | 11⁄2 | 1.500 | 1.450 | 2.121 | 1.991 | 21⁄32 | 0.684 | 0.628 |
| 11⁄8 | 1.149 | 111⁄16 | 1.688 | 1.631 | 2.386 | 2.239 | 3⁄4 | 0.780 | 0.720 |
| 11⁄4 | 1.277 | 17⁄8 | 1.875 | 1.812 | 2.652 | 2.489 | 27⁄32 | 0.876 | 0.812 |
| 13⁄8 | 1.404 | 21⁄16 | 2.062 | 1.994 | 2.917 | 2.738 | 29⁄32 | 0.940 | 0.872 |
| 11⁄2 | 1.531 | 21⁄4 | 2.250 | 2.175 | 3.182 | 2.986 | 1 | 1.036 | 0.964 |
| 13⁄4* | 29⁄16 | 13⁄16 | |||||||
| 2* | 215⁄16 | 15⁄16 | |||||||
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* ASME only defines head dimensions up to 1-1/2". Dimensions for 1-3/4 and 2" are approximate and not covered under the ASME dimensional specifications. Dimensions per ASME B18.2.1 1996 |
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