Nominal Pipe Size (inch) Number of threads per inch Outside Diameter (inch) Outside Diameter (mm) Pitch of thread Depth of thread Truncation, max.”** Pitch diameter at plane of hand-tight engagement Length from end of pipe to plane of hand-tight engagement Length of useful thread Length of washout thread Pitch Diameter at Beginning of External Thread Start (inch) Effective Thread, External Diameter (inch)
        P h l E L1 L2      
        in mm in mm in mm in mm in Threads in Threads in Threads    
1⁄16 27 0.3125 7.938 0.03704 0.941 0.02963 0.753     0.28118   0.16   0.2611   0.1285 3.47 0.27118 0.28750
1/8" 27 0.405 10.287 0.03704 0.941 0.02963 0.753 0.00360 0.091 0.37360 9.489 0.162 4.36 0.2639 7.12 0.1285 3.47 0.36351 0.38000
1/4" 18 0.540 13.716 0.05556 1.411 0.04444 1.129 0.00490 0.124 0.49163 12.487 0.228 4.10 0.4018 7.23 0.1928 3.47 0.47739 0.50250
3/8" 18 0.675 17.145 0.05556 1.411 0.04444 1.129 0.00490 0.124 0.62701 15.926 0.240 4.32 0.4078 7.34 0.1928 3.47 0.61201 0.63750
1/2" 14 0.840 21.336 0.07143 1.814 0.05714 1.451 0.00560 0.142 0.77843 19.772 0.320 4.48 0.5337 7.47 0.2478 3.47 0.75843 0.79179
3/4" 14 1.050 26.670 0.07143 1.814 0.05714 1.451 0.00560 0.142 0.98887 25.117 0.339 4.75 0.5457 7.64 0.2478 3.47 0.96768 1.00179
1" 11.5 1.315 33.401 0.08696 2.209 0.06957 1.767 0.00630 0.160 1.23863 31.461 0.400 4.60 0.6828 7.85 0.3017 3.47 1.21363 1.25630
1-1/4" 11.5 1.660 42.164 0.08696 2.209 0.06957 1.767 0.00630 0.160 1.58338 40.218 0.420 4.83 0.7068 8.13 0.3017 3.47 1.55713 1.60130
1-1/2" 11.5 1.900 48.260 0.08696 2.209 0.06957 1.767 0.00630 0.160 1.82234 46.287 0.402 4.83 0.7235 8.32 0.3017 3.47 1.79609 1.84130
2" 11.5 2.375 60.325 0.08696 2.209 0.06957 1.767 0.00630 0.160 2.29627 58.325 0.436 5.01 0.7565 8.70 0.3017 3.47 2.26902 2.31630
2-1/2" 8 2.875 73.025 0.12500 3.175 0.10000 2.540 0.00780 0.198 2.76215 70.159 0.682 5.46 1.1375 9.10 0.4337 3.47 2.71953 2.79062
3" 8 3.500 88.900 0.12500 3.175 0.10000 2.540 0.00780 0.198 3.38850 86.068 0.766 6.13 1.2000 9.60 0.4337 3.47 3.34062 3.41562
3-1/2" 8 4 101.600 0.12500 3.175 0.10000 2.540 0.00780 0.198 3.88881 98.776 0.821 6.57 1.2500 10.00 0.4337 3.47 3.83750 3.91562
4" 8 4.5 114.300 0.12500 3.175 0.10000 2.540 0.00780 0.198 4.38712 111.433 0.844 6.75 1.3000 10.40 0.4337 3.47 4.33438 4.41562
5" 8 5.563 141.300 0.12500 3.175 0.10000 2.540 0.00780 0.198 5.44929 138.412 0.937 7.50 1.4063 11.25 0.4337 3.47 5.39073 5.47862
6" 8 6.625 168.275 0.12500 3.175 0.10000 2.540 0.00780 0.198 6.50597 165.252 0.958 7.66 1.5125 12.10 0.4337 3.47 6.44609 6.54062
8" 8 8.625 219.075 0.12500 3.175 0.10000 2.540 0.00780 0.198 8.50003 215.901 1.630 8.50 1.7125 13.70 0.4337 3.47 8.43359 8.54062
10" 8 10.750 273.050 0.12500 3.175 0.10000 2.540 0.00780 0.198 10.62094 296.772 1.210 9.58 1.9250 15.40 0.4337 3.47 10.54531 10.66562
12" 8 12.750 323.850 0.12500 3.175 0.10000 2.540 0.00780 0.198 12.61781 320.493 1.360 10.88 2.1250 17.00 0.4337 3.47 12.53281 12.66562
14" 8 14 355.600 0.12500 3.175 0.10000 2.540 0.00780 0.198 13.87262 352.365 1.562 12.50 2.2500 18.00 0.4337 3.47 13.77500 13.91562
16" 8 16 406.400 0.12500 3.175 0.10000 2.540 0.00780 0.198 15.87575 403.244 1.812 14.50 2.4500 19.60 0.4337 3.47 15.76250 15.91562
18" 8 18 457.200 0.12500 3.175 0.10000 2.540 0.00780 0.198 17.87500 454.025 2.000 16.00 2.6500 21.20 0.4337 3.47 17.75000 17.91562
20" 8 20 508.000 0.12500 3.175 0.10000 2.540 0.00780 0.198 19.87031 504.706 2.125 17.00 2.8500 22.80 0.4337 3.47 19.73750 19.91562
24" 8 24 609.600 0.12500 3.175 0.10000 2.540 0.00780 0.198 23.68094 606.066 2.375 19.00 3.2500 26.00 0.4337 3.47 23.71250 23.91562