Hex Head Machine Bolt

Hex head machine bolts are used for fastening pole line hardware and line construction specialty products to cross arm poles and other structures as well as attaching the wooden cross arms to the pole. Hex head machine bolts have an added semi-cone point and a thread length unique to pole line fasteners depending on the bolts length. Hex head machine bolts also have a hex nut assembled.

Hex Machine Bolt Drawing

Click table to show drawing
Bolt Diameter D F C H
Body Diameter Width Across Flats Width Across Corners Height
Max Basic Max Min Max Min Basic Max Min
12 0.515 34 0.750 0.725 0.866 0.826 1132 0.364 0.302
58 0.642 1516 0.938 0.906 1.083 1.033 2764 0.444 0.378
34 0.768 118 1.125 1.088 1.299 1.240 12 0.524 0.455
78 0.895 1516 1.312 1.269 1.516 1.447 3764 0.604 0.531
1 1.022 112 1.500 1.450 1.732 1.653 4364 0.700 0.591
118 1.149 11116 1.688 1.631 1.949 1.859 34 0.780 0.658
114 1.277 178 1.875 1.812 2.165 2.066 2732 0.876 0.749
138 1.404 2116 2.062 1.994 2.382 2.273 2932 0.940 0.810
112 1.531 214 2.250 2.175 2.598 2.480 1 1.036 0.902
158 1.658 2716 2.438 2.356 2.815 2.616 1332 1.116 0.978
134 1.785 2-5/8 2.625 2.538 3.031 2.893 1532 1.196 1.054
178 1.912 21316 2.812 2.719 3.248 3.099 114 1.276 1.130
2 2.039 3 3.000 2.900 3.464 3.306 11132 1.388 1.175
214 2.305 338 3.375 3.262 3.897 3.719 112 1.548 1.327
212 2.559 334 3.750 3.625 4.330 4.133 12132 1.708 1.479
Dimensions per ASME B18.2.1 2010

Standard Thread Lengths

*Bolts shorter and/or smaller than those listed in the table shall have minimum thread lengths in accordance with American National Standard for Square and  Hex Bolts and Screws, B18.2.1*
Diameters Bolt length Thread length
  • 3/8"
  • 1/2"
  • 5/8"
  • 3/4"
  • 7/8"
  • 1"
4" up to less than 8" 3"
  • 3/8"
  • 1/2"
  • 5/8"
  • 3/4"
  • 7/8"
  • 1"
  • 1-1/4"
8" up to less than 12" 4"
  • 3/8"
  • 1/2"
  • 5/8"
  • 3/4"
  • 7/8"
  • 1"
  • 1-1/4"
12" and over 6"