HEX NUT DIMENSIONS TABLE

Hex nut dimensions sizes table according to ASME B18.2.2. All dimensions are given in inches. Hex and jam nut thickness are given for nut sizes between 1/4 to 4 inches.

Hex Nut Dimensions
Nominal
 Size		 Basic
Major
Diameter
of
Thread 		 F G H H1
Width
Across
Flats		 Width
Across
Corners		 Thickness
Hex
Nut		 Thickness
Jam
Nut
min max. min. max. min. max. min. max.
1/4 0.2500 0.428 0.438 0.488 0.505 0.212 0.226 0.150 0.163
5/16 0.3125 0.489 0.500 0.557 0.577 0.258 0.273 0.180 0.195
3/8 0.3750 0.551 0.563 0.628 0.650 0.320 0.337 0.210 0.227
7/16 0.4375 0.675 0.688 0.768 0.794 0.365 0.385 0.240 0.260
1/2 0.5000 0.736 0.750 0.840 0.866 0.427 0.448 0.302 0.323
9/16 0.5625 0.861 0.875 0.982 1.010 0.473 0.496 0.301 0.324
5/8 0.6250 0.922 0.938 1.051 1.083 0.535 0.559 0.363 0.387
3/4 0.7500 1.088 1.125 1.240 1.299 0.617 0.665 0.398 0.446
7/8 0.8750 1.269 1.312 1.447 1.516 0.724 0.776 0.458 0.510
1 1.0000 1.450 1.500 1.653 1.732 0.831 0.887 0.519 0.575
Nominal
 Size		 Major
Diameter
of
Thread  		 F G H H1
Width
Across
Flats		 Width
Across
Corners		 Thickness
Hex
Nut		 Thickness
Jam
Nut
min max. min. max. min. max. min. max.
1 1/8 1.1250 1.631 1.688 1.859 1.949 0.939 0.999 0.579 0.639
1 1/4 1.2500 1.812 1.875 2.066 2.165 1.030 1.094 0.687 0.751
1 3/8 1.3750 1.994 2.062 2.273 2.382 1.138 1.206 0.747 0.815
1 1/2 1.5000 2.175 2.250 2.480 2.598 1.245 1.317 0.808 0.880
1 5/8 1.6250 2.35 2.43 2.679 2.805 1.364 1.416 0.868 0.944
1 3/4 1.7500 2.538 2.625 2.893 3.031 1.460 1.540 0.929 1.009
1 7/8 1.8750 2.722 2.813 3.103 3.247 1.567 1.651 0.989 1.073
Nominal
 Size		 Major
Diameter
of
Thread  		 F G H H1
Width
Across
Flats		 Width
Across
Corners		 Thickness
Hex
Nut		 Thickness
Jam
Nut
min max. min. max. min. max. min. max.
2 2.0000 2.900 3.000 3.306 3.464 1.675 1.763 1.050 1.138
2 1/4 2.2500 3.263 3.375 3.719 3.897 1.890 1.986 1.155 1.267
2 1/2 2.5000 3.625 3.750 4.133 4.330 2.105 2.209 1.401 1.427
2 3/4 2.7500 3.988 4.125 4.546 4.763 2.319 2.431 1.522 1.556
3 3.0000 4.350 4.500 4.959 5.196 2.534 2.654 1.643 1.685
3 1/4 3.2500 4.713 4.875 5.373 5.629 2.749 2.877 1.748 1.814
3 1/2 3.5000 5.075 5.250 5.786 6.062 2.964 3.100 1.870 1.943
3 3/4 3.7500 5.438 5.625 6.199 6.495 3.178 3.322 1.990 2.072
4 4.0000 5.800 6.000 6.612 6.928 3.393 3.545 2.112 2.201

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)