Heavy hex nuts are slightly larger and thicker than standard (finished) hex nuts. There are numerous grades and the heavy pattern is typically used for large diameter and high strength bolts. See our nut compatibility chart to determine the compatible heavy hex nut(s) for a specific grade of bolt. Since hot-dip galvanizing typically adds 2.2 to 5 mils of thickness to the threaded portion of a fastener, galvanized heavy hex nuts are tapped oversize to compensate for the corrosion resistant coating on the bolts.

Stock

Diameters: 3/8″ – 2-3/4″
Origin: Domestic and import
Finish: Plain and hot-dip galvanized
Grades: A563 (grades A, C, and DH), A194 grade 2H

Dimensions

Click table to show drawingHeavy Hex Nut
Bolt Diam. F C H Weight
(lbs.)
Part Numbers
Width Across Flats Width Across Corners Thickness A563A A1942H A563DH
Domestic Import Domestic Import Domestic
Basic Max Min Max Min Basic Max Min Plain Galv. Plain Galv. Plain Galv. Plain Galv. Plain Galv.
12 78 0.875 0.850 1.010 0.969 3164 0.504 0.464 0.07 - 19505 11729 11730 16356 - 11761 11762 - 18345
58 1116 1.062 1.031 1.227 1.175 3964 0.631 0.587 0.12 - - 11731 11732 16358 16359 11763 11764 - 18346
34 114 1.250 1.212 1.443 1.382 4764 0.758 0.710 0.20 16306 16307 11733 11734 16360 16361 11765 11766 - 18347
78 1716 1.438 1.394 1.660 1.589 5564 0.885 0.833 0.30 16308 16309 11735 11736 16362 16363 11767 11768 - 18348
1 158 1.625 1.575 1.876 1.796 6364 1.012 0.956 0.43 16310 16311 11737 11738 16364 16365 11769 11770 - 18349
118 11316 1.812 1.756 2.093 2.002 1764 1.139 1.079 0.59 16312 16313 11739 11740 16366 - 11771 11772 - 16367
114 2 2.000 1.938 2.309 2.209 1732 1.251 1.187 0.79 16314 16315 11741 11742 16370 - 11773 11774 - 16371
138 2316 2.188 2.119 2.526 2.416 11132 1.378 1.310 1.02 - - 11743 11744 16374 - 11775 11776 - 16375
112 238 2.375 2.300 2.742 2.622 11532 1.505 1.433 1.31 16318 16319 11745 11746 16378 - 11777 11778 - 16379
158 2916 2.562 2.481 2.959 2.828 11932 1.632 1.556 1.62 - - 17750 17751 16380 16381 11779 11780 16380 16381
134 234 2.750 2.662 3.175 3.035 12332 1.759 1.679 2.04 16322 16323 11747 11748 16384 16385 12549 12550 16384 16385
178 21516 2.938 2.844 3.392 3.242 12732 1.886 1.802 2.41 - - 19433 19434 - - - - - -
2 318 3.125 3.025 3.608 3.449 13132 2.013 1.925 2.99 16324 16325 11749 11750 16390 16391 11783 11784 16390 16391
214 312 3.500 3.388 4.041 3.862 21364 2.251 2.155 4.19 16326 16327 11751 11752 16396 16397 12681 12682 16396 16397
212 378 3.875 3.750 4.474 4.275 22964 2.505 2.401 5.64 16328 16329 11753 11754 16398 16399 12553 12554 16398 16399
234 414 4.250 4.112 4.907 4.688 24564 2.759 2.647 7.38 16330 16331 15864  16041 16400 16401 12555 12556 16400 16401
3 458 4.625 4.475 5.340 5.102 26164 3.013 2.893 9.50 19294 19308 15863 16042 16402 16403 12601 12602 16402 16403
314 5 5.000 4.838 5.774 5.515 3316 3.252 3.124 11.94 - - 18395 - - - - - - -
312 538 5.375 5.200 6.207 5.928 3716 3.506 3.370 15.26 - - 18495 - - - - - - -
334 534 5.750 5.562 6.640 6.341 31116 3.760 3.616 18.12 - - - - - - - - - -
4 618 6.125 5.925 7.073 6.755 31516 4.014 3.862 21.80 - - 11755 11756 16404 16405 - - 16404 16405

Dimensions per ASME B18.2.2 1987 (1999)