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Standard Thread Length
Bolt lengths ≤ 6": Thread length = (2 X diameter) + 1/4"
Bolt lengths > 6": Thread length = (2 X diameter) + 1/2"
Note: Most stock hex bolts 10" and longer will have 6" of thread.
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 | |
3/8 | 0.388 | 9/16 | 0.562 | 0.544 | 0.650 | 0.620 | 1/4 | 0.268 | 0.226 |
1/2 | 0.515 | 3/4 | 0.750 | 0.725 | 0.866 | 0.826 | 11/32 | 0.364 | 0.302 |
5/8 | 0.642 | 15/16 | 0.938 | 0.906 | 1.083 | 1.033 | 27/64 | 0.444 | 0.378 |
3/4 | 0.768 | 1-1/8 | 1.125 | 1.088 | 1.299 | 1.240 | 1/2 | 0.524 | 0.455 |
7/8 | 0.895 | 1-5/16 | 1.312 | 1.269 | 1.516 | 1.447 | 37/64 | 0.604 | 0.531 |
1 | 1.022 | 1-1/2 | 1.500 | 1.450 | 1.732 | 1.653 | 43/64 | 0.700 | 0.591 |
1-1/8 | 1.149 | 1-11/16 | 1.688 | 1.631 | 1.949 | 1.859 | 3/4 | 0.780 | 0.658 |
1-1/4 | 1.277 | 1-7/8 | 1.875 | 1.812 | 2.165 | 2.066 | 27/32 | 0.876 | 0.749 |
1-3/8 | 1.404 | 2-1/16 | 2.062 | 1.994 | 2.382 | 2.273 | 29/32 | 0.940 | 0.810 |
1-1/2 | 1.531 | 2-1/4 | 2.250 | 2.175 | 2.598 | 2.480 | 1 | 1.036 | 0.902 |
1-3/4 | 1.785 | 2-5/8 | 2.625 | 2.538 | 3.031 | 2.893 | 1-5/32 | 1.196 | 1.054 |
2 | 2.039 | 3 | 3.000 | 2.900 | 3.464 | 3.306 | 1-11/32 | 1.388 | 1.175 |
2-1/4 | 2.305 | 3-3/8 | 3.375 | 3.262 | 3.897 | 3.719 | 1-1/2 | 1.548 | 1.327 |
2-1/2 | 2.559 | 3-3/4 | 3.750 | 3.625 | 4.330 | 4.133 | 1-21/32 | 1.708 | 1.479 |
Dimensions per ASME B18.2.1 1996
Stainless Steel Hex Bolt
