HEX NUT DIMENSIONS TABLE


Hex nut dimensions sizes table according to ASME B18.2.2. All dimensions are given in inches. Width across flats (wrench size) and corners and 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:

Link Usage
Hex nut dimensions calculator Calculator form of the hex nut dimensions chart.


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)