HEAVY HEX NUT DIMENSIONS TABLE

Heavy hex nut dimensions according to ASME B18.2.2 for nut sizes between 1/4 to 4 inches. All dimensions are given in inches.

Hex Nut Dimensions
Nominal
 Size		 Basic
Major
Diameter
of
Thread 		 F G H H1
Width
Across
Flats		 Width
Across
Corners		 Thickness 
Heavy
Hex
Nut		 Thickness
Heavy
Hex
Jam
Nuts
Basic min max. min. max. Basic min. max. Basic min. max.
1/4 0.2500 1/2 0.488 0.500 0.556 0.577 15/64 0.218 0.250 11/64 0.156 0.188
5/16 0.3125 9/16 0.546 0.562 0.622 0.650 19/64 0.280 0.314 13/64 0.186 0.220
3/8 0.3750 11/16 0.669 0.688 0.763 0.794 23/64 0.341 0.377 15/64 0.216 0.252
7/16 0.4375 3/4 0.728 0.750 0.830 0.866 27/64 0.403 0.441 17/64 0.247 0.285
1/2 0.5000 7/8 0.850 0.875 0.969 1.010 31/64 0.464 0.504 19/64 0.277 0.317
9/16 0.5625 15/16 0.909 0.938 1.037 1.083 35/64 0.526 0.568 21/64 0.307 0.349
5/8 0.6250 1 1/16 1.031 1.062 1.175 1.227 39/64 0.587 0.631 23/64 0.337 0.381
3/4 0.7500 1 1/4 1.212 1.250 1.382 1.443 47/64 0.710 0.758 27/64 0.398 0.446
7/8 0.8750 1 7/16 1.394 1.438 1.589 1.660 55/64 0.833 0.885 31/64 0.458 0.510
1 1.0000 1 5/18 1.575 1.625 1.796 1.876 63/64 0.956 1.012 35/64 0.519 0.575
Nominal
 Size		 Major
Diameter
of
Thread  		 F G H H1
Width
Across
Flats		 Width
Across
Corners		 Thickness 
Heavy
Hex
Nut		 Thickness
Heavy
Hex
Jam
Nuts
Basic min max. min. max. Basic min. max. Basic min. max.
1 1/8 1.1250 1 13/16 1.756 1.812 2.002 2.093 1 7/64 1.079 1.139 39/64 0.579 0.639
1 1/4 1.2500 2 1.938 2.000 2.209 2.309 1 7/32 1.187 1.251 23/32 0.687 0.751
1 3/8 1.3750 2 3/16 2.119 2.188 2.416 2.526 1 11/32 1.310 1.378 25/32 0.747 0.815
1 1/2 1.5000 2 3/8 2.300 2.375 2.622 2.742 1 15/32 1.433 1.505 27/32 0.808 0.880
1 5/8 1.6250 2 9/16 2.481 2.562 2.828 2.959 1 19/32 1.556 1.632 29/32 0.868 0.944
1 3/4 1.7500 2 3/4 2.662 2.750 3.035 3.175 1 23/32 1.679 1.759 31/32 0.929 1.009
1 7/8 1.8750 2 15/16 2.844 2.938 3.242 3.392 1 27/32 1.802 1.886 1 1/32 0.989 1.073
Nominal
 Size		 Major
Diameter
of
Thread  		 F G H H1
Width
Across
Flats		 Width
Across
Corners		 Thickness 
Heavy
Hex
Nut		 Thickness
Heavy
Hex
Jam
Nuts
Basic min max. min. max. Basic min. max. Basic min. max.
2 2.0000 3 1/8 3.025 3.125 3.449 3.608 1 31/32 1.925 2.013 1 3/32 1.050 1.138
2 1/4 2.2500 3 1/2 3.388 3.500 3.862 4.041 2 13/64 2.155 2.251 1 13/64 1.155 1.251
2 1/2 2.5000 3 7/8 3.750 3.875 4.275 4.474 2 29/64 2.401 2.505 1 29/64 1.401 1.505
2 3/4 2.7500 4 1/4 4.112 4.250 4.688 4.907 2 45/64 2.647 2.759 1 37/64 1.522 1.634
3 3.0000 4 5/8 4.475 4.625 5.102 5.340 2 61/64 2.893 3.013 1 45/64 1.643 1.763
3 1/4 3.2500 5 4.838 5.000 5.515 5.774 3 3/16 3.124 3.252 1 13/16 1.748 1.876
3 1/2 3.5000 5 3/8 5.200 5.375 5.928 6.207 3 7/16 3.370 3.506 1 15/16 1.870 2.006
3 3/4 3.7500 5 3/4 5.562 5.750 6.341 6.640 3 11/16 3.616 3.760 2 1/16 1.990 2.134
4 4.0000 6 1/8 5.925 6.125 6.755 7.073 3 15/16 3.862 4.014 2 3/16 2.112 2.264

Supplements:

Reference:

  • Oberg, E. , Jones ,F.D. , Horton H.L. , Ryffel H.H., (2016) . Machinery's Handbook . 30th edition.  Industrial Press Inc. , pp 1595
  • ASME B18.2.2-2010, Square and Hex Nuts (Inch Series)