ASTM A194 Grade 2H Coupling Nuts B18.2.2

High Temperature Carbon Steel Nuts

Coupling Nuts B18.2.2

Coupling Nuts B18.2.2

Dimensions of Coupling Nuts B18.2.2

Nominal Size
Inch
Basic Major
Thread Diameter
Width Across Flats, F Width Across Corners, C 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 2-1/2 in. and smaller, and 1 in. for sizes 2-3/4 in. and larger.