Several ASTM specifications require a hex head that is larger than a standard (finished) hex head. These specifications include: A193, A320 and A307B. Although A325 and A490 bolts also require a heavy hex head, please refer to Structural Bolts for dimensional specifications, since these bolts have shorter thread lengths than standard heavy hex bolts.


Applications:

Heavy hex bolts can be used for many different applications that include fastening wood, steel, and other construction materials for projects such as docks, bridges, highway structures and buildings. Heavy hex bolts with forged heads are also commonly used as headed anchor bolts.

Manufacturing:

Fastindo Wiratama manufactures heavy hex bolts from 1/2″ diameter through 2-1/2″ diameter in most ASTM, AASHTO, and SAE specifications. Special tooling can be created to produce nonstandard head dimensions or bolt heads with your company’s name and/or logo.

Stock:

Fastindo Wiratama 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
These sizes are readily available in the marketplace and Fastindo Wiratama stocks many of them in varying quantities. If you require a size that is not listed, Fastindo Wiratama will manufacture them.