ASME B18.2.2 Hex Coupling Nuts
Dimensions of Hex Coupling Nuts
| Nominal Size | Basic Major Diameter of Thread | Width Across Flats, F | Width Across Corners, G | Length, H | |||||
|---|---|---|---|---|---|---|---|---|---|
| Basic | Min. | Max. | Min. | Max. | Basic | Min. | Max. | ||
| #6 | 0.138 | 5/16 | 0.302 | 0.312 | 0.344 | 0.361 | 1/2 | 0.470 | 0.510 |
| #8 | 0.164 | 5/16 | 0.302 | 0.312 | 0.344 | 0.361 | 5/8 | 0.595 | 0.645 |
| #10 | 0.190 | 5/16 | 0.302 | 0.312 | 0.344 | 0.361 | 3/4 | 0.711 | 0.760 |
| 1/4 | 0.250 | 7/16 | 0.428 | 0.438 | 0.438 | 0.488 | 1 3/4 | 1.690 | 1.760 |
| 5/16 | 0.312 | 1/2 | 0.489 | 0.500 | 0.557 | 0.577 | 1 3/4 | 1.690 | 1.760 |
| 3/8 | 0.375 | 9/16 | 0.551 | 0.562 | 0.628 | 0.650 | 1 3/4 | 1.690 | 1.760 |
| 7/16 | 0.437 | 5/8 | 0.607 | 0.625 | 0.692 | 0.722 | 1 3/4 | 1.690 | 1.760 |
| 1/2 | 0.500 | 11/16 | 0.663 | 0.688 | 0.756 | 0.794 | 1 3/4 | 1.690 | 1.760 |
| 9/16 | 0.562 | 13/16 | 0.782 | 0.813 | 0.891 | 0.939 | 2 1/8 | 2.067 | 2.135 |
| 5/8 | 0.625 | 13/16 | 0.782 | 0.813 | 0.891 | 0.939 | 2 1/8 | 2.067 | 2.135 |
| 3/4 | 0.750 | 1 | 0.963 | 1.000 | 1.097 | 1.155 | 2 1/4 | 2.190 | 2.260 |
| 7/8 | 0.875 | 1 1/4 | 1.212 | 1.250 | 1.382 | 1.443 | 2 1/2 | 2.440 | 2.510 |
| 1 | 1.000 | 1 3/8 | 1.325 | 1.375 | 1.511 | 1.588 | 2 3/4 | 2.690 | 2.760 |
| 1 1/8 | 1.125 | 1 1/2 | 1.450 | 1.500 | 1.653 | 1.732 | 3 | 2.940 | 3.010 |
| 1 1/4 | 1.250 | 1 5/8 | 1.575 | 1.625 | 1.825 | 1.876 | 3 | 2.940 | 3.010 |
| 1 1/2 | 1.500 | 2 | 1.950 | 2.000 | 2.275 | 2.309 | 3 1/2 | 3.440 | 3.510 |
| 1 5/8 | 1.625 | 2 9/16 | 2.481 | 2.562 | 2.828 | 2.959 | 4 7/8 | 4.830 | 4.900 |
| 1 3/4 | 1.750 | 2 3/4 | 2.662 | 2.750 | 3.035 | 3.175 | 5 1/4 | 5.210 | 5.290 |
| 1 7/8 | 1.875 | 2 15/16 | 2.844 | 2.938 | 3.242 | 3.392 | 5 5/8 | 5.580 | 5.670 |
| 2 | 2.000 | 3 1/8 | 3.025 | 3.125 | 3.448 | 3.608 | 6 | 5.950 | 6.040 |
| 2 1/4 | 2.250 | 3 1/2 | 3.388 | 3.500 | 3.862 | 4.041 | 6 3/4 | 6.700 | 6.800 |
| 2 1/2 | 2.500 | 3 7/8 | 3.750 | 3.875 | 4.275 | 4.474 | 7 1/2 | 7.440 | 7.550 |
| 2 3/4 | 2.750 | 4 1/4 | 4.112 | 4.250 | 4.688 | 4.907 | 8 1/4 | 8.190 | 8.310 |
| 3 | 3.000 | 4 5/8 | 4.475 | 4.625 | 5.101 | 5.340 | 9 | 8.940 | 9.060 |
| 3 1/4 | 3.250 | 5 | 4.838 | 5.000 | 5.515 | 5.773 | 9 3/4 | 9.680 | 9.810 |
| 3 1/2 | 3.500 | 5 3/8 | 5.200 | 5.375 | 5.928 | 6.206 | 10 1/2 | 10.430 | 10.570 |
| 3 3/4 | 3.750 | 5 3/4 | 5.562 | 5.750 | 6.340 | 6.639 | 11 1/4 | 11.170 | 11.320 |
| 4 | 4.000 | 6 1/8 | 5.925 | 6.125 | 6.754 | 7.072 | 12 | 11.920 | 12.080 |
| 4 1/4 | 4.250 | 6 1/2 | 6.288 | 6.500 | 7.168 | 7.506 | 12 3/4 | 12.670 | 12.830 |
| 4 1/2 | 4.500 | 6 7/8 | 6.650 | 6.875 | 7.581 | 7.939 | 13 1/2 | 13.420 | 13.580 |
| 4 3/4 | 4.750 | 7 1/4 | 7.012 | 7.250 | 7.994 | 8.372 | 14 1/4 | 14.160 | 14.340 |
| 5 | 5.000 | 7 5/8 | 7.375 | 7.625 | 8.408 | 8.805 | 15 | 14.910 | 15.090 |
| 5 1/4 | 5.250 | 8 | 7.738 | 8.000 | 8.821 | 9.238 | 15 3/4 | 15.650 | 15.850 |
| 5 1/2 | 5.500 | 8 3/8 | 8.100 | 8.375 | 9.234 | 9.671 | 16 1/2 | 16.400 | 16.600 |
| 5 3/4 | 5.750 | 8 3/4 | 8.462 | 8.750 | 9.647 | 10.104 | 17 1/4 | 17.150 | 17.350 |
| 6 | 6.000 | 9 1/8 | 8.825 | 9.125 | 10.060 | 10.537 | 18 | 17.890 | 18.110 |
Note :
Nuts shall be furnished without a hole, unless specially order by the purchaser. In some applications it may be desirable to assure that the threaded parts joined by a coupling nut are each engaged to approximately one-half nut thickness. As a visual inspection aid, a hole drilled through one side of the nut is recommended. The hole should be located at mid-nut thickness, and have a diameter of 0.2 to 0.4 times nominal nut size for sizes 21/2 in. and smaller, and 1 in. for sizes 23/4 in. and larger.