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Heavy Jam Nuts

Heavy Jam Nut

Heavy hex jam nuts are thinner than a standard heavy hex nut but have the same dimension across the flats and corners. Heavy hex jam nuts have two common applications. A heavy hex jam nut can be threaded onto a bolt and run tight against the standard heavy hex nut which will lock the nut in place and prevent it from backing off. Heavy hex jam nuts are sometimes used for leveling purposes as well. Since hot-dip galvanizing typically adds 2.2 to 5 mils of thickness to the threaded portion of a fastener, galvanized heavy hex jam nuts are tapped oversize to compensate for the corrosion-resistant coating on the bolts.

Available

Diameters: 1/2″ – 2″
Origin: Import
Finish: Plain and hot-dip galvanized

Dimensions

Click table to show drawingHeavy Hex Jam Nut
Nominal Size F C H Part Numbers
Width Across Flats Width Across Corners Thickness
Basic Max Min Max Min Basic Max Min Plain Galvanized
3⁄8 11⁄16 0.688 0.669 0.794 0.763 15⁄64 0.252 0.216 - -
1⁄2 7⁄8 0.875 0.850 1.010 0.969 19⁄64 0.317 0.277 - -
5⁄8 11⁄16 1.062 1.031 1.227 1.175 23⁄64 0.381 0.337 - -
3⁄4 11⁄4 1.250 1.212 1.443 1.382 27⁄64 0.446 0.398 - 18404
7⁄8 17⁄16 1.438 1.394 1.660 1.589 31⁄64 0.510 0.458 - -
1 15⁄8 1.625 1.575 1.876 1.796 35⁄64 0.575 0.519 17112 17113
11⁄8 113⁄16 1.812 1.756 2.093 2.002 39⁄64 0.639 0.579 - -
11⁄4 2 2.000 1.938 2.309 2.209 23⁄32 0.751 0.687 17114 17115
13⁄8 213⁄16 2.188 2.119 2.526 2.416 25⁄32 0.815 0.747 - -
11⁄2 23⁄8 2.375 2.300 2.742 2.622 27⁄32 0.880 0.808 17116 17117
15⁄8 29⁄16 2.562 2.481 2.959 2.828 29⁄32 0.944 0.868 - -
13⁄4 23⁄4 2.750 2.662 3.175 3.035 31⁄32 1.009 0.929 17118 17119
17⁄8 215⁄16 2.938 2.844 3.392 3.242 11⁄32 1.073 0.989 - -
2 31⁄8 3.125 3.025 3.608 3.449 13⁄32 1.138 1.050 17120 17121
21⁄4 31⁄2 3.500 3.388 4.041 3.862 113⁄64 1.251 1.155 19847 19846
21⁄2 37⁄8 3.875 3.750 4.474 4.275 129⁄64 1.505 1.401 - -
23⁄4 41⁄4 4.250 4.112 4.907 4.688 137⁄64 1.634 1.522 - -
3 45⁄8 4.625 4.475 5.340 5.102 145⁄64 1.763 1.643 - -
31⁄4 5 5.000 4.838 5.774 5.515 113⁄16 1.876 1.748 - -
31⁄2 53⁄8 5.375 5.200 6.207 5.928 115⁄16 2.006 1.870 - -
33⁄4 53⁄4 5.750 5.562 6.640 6.341 21⁄16 2.134 1.990 - -
4 61⁄8 6.125 5.925 7.073 6.755 23⁄16 2.264 2.112 - -

Dimensions per ASME B18.2.2 1987 (R 1999)