Machine bolts, also known as cross arm bolts, are used primarily in the pole line domain. Machine bolts possess square heads & a semi-cone point. They generally have a square nut assembled. Moreover, they are usually hot dip galvanized so as to secure the steel. At Baseline, we manufacture machine bolts up to 1-1/2″ diameter. These bolts seem to follow the guidelines pertaining to thread length, largely used in case of pole line fasteners.

Machine Bolt Dimensions

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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 1.061 0.995 2164 0.348 0.308
58 0.642 1516 0.938 0.906 1.326 1.244 2764 0.444 0.400
34 0.768 118 1.125 1.088 1.591 1.494 12 0.524 0.476
78 0.895 1516 1.312 1.269 1.856 1.742 1932 0.620 0.568
1 1.022 112 1.500 1.450 2.121 1.991 2132 0.684 0.628
118 1.149 11116 1.688 1.631 2.386 2.239 34 0.780 0.720
114 1.277 178 1.875 1.812 2.652 2.489 2732 0.876 0.812
138 1.404 2116 2.062 1.994 2.917 2.738 2932 0.940 0.872
112 1.531 214 2.250 2.175 3.182 2.986 1 1.036 0.964
134* 2916 1316
2* 21516 1516

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.