Cross arm or machine bolts are used in the pole line industry. They have square heads and a semi-cone point and typically come with a square nut assembled. They are also typically hot-dip galvanized in order to protect the steel. We can manufacture cross arm bolts up to 1-1/2″ in diameter. Cross arm bolts follow the thread length guidelines used for pole line fasteners. More information about machine bolts is available on our educational microsite polelinefasteners.com.


Machine Bolt 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
Dimensions per ASME B18.2.1 1996
* 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.