A few ASTM specifications demand a hex head which is larger compared to a standard finished hex head. Specifications include A193, A320 & A307B. While A325 & A490 bolts also demand a heavy hex head, it is important to refer to Structural Bolts to learn the dimensional specifications because these bolts tend to exhibit shorter thread lengths compared to standard heavy hex bolts.
Applications
These heavy hex bolts have a range of different applications including fastening steel, wood and various other construction materials, especially for projects including bridges, docks, buildings and highway structures. Hex bolts that come with forged heads are generally used as headed anchor bolts as well.
Manufacturing
Baseline Bolt manufactures high quality heavy hex bolts of diameter 1/2″ - 2-1/2″, fulfilling most of the ASTM, AASHTO & SAE specifications. What’s more, it is possible to create special tooling so as to produce nonstandard head dimensions / bolt heads with the name and/or logo of your company or business.
Stock
Baseline Bolt stocks A325 Heavy Hex Structural Bolts.
Standard Thread Lengths
Bolt lengths ≤ 6″: Thread length = (2 X diameter) + 1/4″
Bolt lengths > 6″: Thread length = (2 X diameter) + 1/2″
Heavy Hex 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 | 7⁄8 | 0.875 | 0.850 | 1.010 | 0.969 | 11⁄32 | 0.364 | 0.302 |
| 5⁄8 | 0.642 | 11⁄16 | 1.062 | 1.031 | 1.227 | 1.175 | 27⁄64 | 0.444 | 0.378 |
| 3⁄4 | 0.768 | 11⁄4 | 1.250 | 1.212 | 1.443 | 1.383 | 1⁄2 | 0.524 | 0.455 |
| 7⁄8 | 0.895 | 17⁄16 | 1.438 | 1.394 | 1.660 | 1.589 | 37⁄64 | 0.604 | 0.531 |
| 1 | 1.022 | 15⁄8 | 1.625 | 1.575 | 1.876 | 1.796 | 43⁄64 | 0.700 | 0.591 |
| 11⁄8 | 1.149 | 113⁄16 | 1.812 | 1.756 | 2.093 | 2.002 | 3⁄4 | 0.780 | 0.658 |
| 11⁄4 | 1.277 | 2 | 2.00 | 1.938 | 2.309 | 2.209 | 27⁄32 | 0.876 | 0.749 |
| 13⁄8 | 1.404 | 23⁄16 | 2.188 | 2.119 | 2.526 | 2.416 | 29⁄32 | 0.940 | 0.810 |
| 11⁄2 | 1.531 | 23⁄8 | 2.375 | 2.300 | 2.742 | 2.622 | 1 | 1.036 | 0.902 |
| 15⁄8 | 1.658 | 29⁄16 | 2.562 | 2.481 | 2.959 | 2.829 | 13⁄32 | 1.116 | 0.978 |
| 13⁄4 | 1.785 | 23⁄4 | 2.750 | 2.662 | 3.175 | 3.035 | 15⁄32 | 1.196 | 1.054 |
| 17⁄8 | 1.912 | 215⁄16 | 2.938 | 2.844 | 3.392 | 3.242 | 11⁄4 | 1.276 | 1.130 |
| 2 | 2.039 | 31⁄8 | 3.125 | 3.025 | 3.608 | 3.449 | 111⁄32 | 1.388 | 1.175 |
| 21⁄4 | 2.305 | 31⁄2 | 3.500 | 3.388 | 4.041 | 3.862 | 11⁄2 | 1.548 | 1.327 |
| 21⁄2 | 2.559 | 37⁄8 | 3.875 | 3.750 | 4.474 | 4.275 | 121⁄32 | 1.708 | 1.479 |
|
Dimensions per ASME B18.2.1 2010 |
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