ASME B18.31.2 Tap End Reduced Body Studs
ASME B18.31.2 Dimensions for Tap End Reduced Body Studs (mm)
| Nominal Size |
Diameter, D |
Minimum Nut-End Full Thread Length, Bmin |
Maximum Body Diameter, DR , for Reduced- Body Studs |
Minimum Body Diameter, DR , for Reduced- Body Studs |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| L ≤ 254 mm (10 in) |
254 < L ≤ 406.4 mm (10 < L ≤ 16 in) |
L > 406.4 mm (16 in) |
UNC and NC-5 HF Threads |
UNF Threads |
8UN Threads |
UNC and NC-5 HF Threads |
UNF Threads |
8UN Threads | ||
| ¼ | 6.350 | 19.050 | 25.400 | 38.100 | 6.121 | 6.172 | … | 5.410 | 5.664 | … |
| 5/16 | 7.938 | 22.225 | 28.575 | 41.275 | 7.696 | 7.722 | … | 6.883 | 7.137 | … |
| 3/8 | 9.525 | 25.400 | 31.750 | 44.450 | 9.246 | 9.322 | … | 8.357 | 8.712 | … |
| 7/16 | 11.112 | 28.575 | 34.925 | 47.625 | 10.820 | 10.871 | … | 9.779 | 10.160 | … |
| ½ | 12.700 | 31.750 | 38.100 | 50.800 | 12.395 | 12.471 | … | 11.278 | 11.735 | … |
| 9/16 | 14.287 | 34.925 | 41.275 | 53.975 | 13.970 | 14.021 | … | 12.751 | 13.233 | … |
| 5/8 | 15.875 | 38.100 | 44.450 | 57.150 | 15.519 | 15.621 | … | 14.199 | 14.808 | … |
| ¾ | 19.050 | 44.450 | 50.800 | 63.500 | 18.669 | 18.771 | … | 17.196 | 17.856 | … |
| 7/8 | 22.225 | 50.800 | 57.150 | 69.850 | 21.819 | 21.920 | … | 20.193 | 20.879 | … |
| 1 | 25.400 | 57.150 | 63.500 | 76.200 | 24.968 | 25.070 | … | 23.114 | 23.825 | … |
| 1⅛ | 28.575 | 63.500 | 69.850 | 82.550 | 28.092 | 28.245 | 28.143 | 25.984 | 27.000 | 26.289 |
| 1¼ | 31.750 | 69.850 | 76.200 | 88.900 | 31.267 | 31.420 | 31.318 | 29.159 | 30.175 | 29.464 |
| 1⅜ | 34.925 | 76.200 | 82.550 | 95.250 | 34.392 | 34.595 | 34.493 | 31.902 | 33.350 | 32.614 |
| 1½ | 38.100 | 82.550 | 88.900 | 101.600 | 37.567 | 37.770 | 37.668 | 35.077 | 36.525 | 35.789 |
| 1⅝ | 41.275 | 88.900 | 95.250 | 107.950 | … | … | 40.843 | … | … | 38.964 |
| 1¾ | 44.450 | 95.250 | 101.600 | 114.300 | 43.866 | … | 44.018 | 40.869 | … | 42.139 |
| 1⅞ | 47.625 | 101.600 | 107.950 | 120.650 | … | … | 47.193 | … | … | 45.314 |
| 2 | 50.800 | 107.950 | 114.300 | 127.000 | 50.165 | … | 50.368 | 46.812 | … | 48.489 |
| 2¼ | 57.150 | 120.650 | 127.000 | 139.700 | 56.515 | … | 56.718 | 53.162 | … | 54.813 |
| 2½ | 63.500 | 133.350 | 139.700 | 152.400 | 62.814 | … | 63.068 | 59.030 | … | 61.163 |
| 2¾ | 69.850 | 146.050 | 152.400 | 165.100 | 69.164 | … | 69.418 | 65.380 | … | 67.513 |
| 3 | 76.200 | … | 165.100 | 177.800 | 75.514 | … | 75.743 | 71.730 | … | 73.863 |
| 3¼ | 82.550 | … | 177.800 | 190.500 | 81.864 | … | 82.093 | 78.054 | … | 80.213 |
| 3½ | 88.900 | … | 190.500 | 203.200 | 88.214 | … | 88.443 | 84.404 | … | 86.538 |
| 3¾ | 95.250 | … | 203.200 | 215.900 | 94.564 | … | 94.793 | 90.754 | … | 92.888 |
| 4 | 101.600 | … | 215.900 | 228.600 | 100.914 | … | 101.143 | 97.104 | … | 99.238 |
ASME B18.31.2 Tap End Stud Reduced Body Length Tolerances
| Range, LT | Tap-End Studs Tolerance |
|---|---|
| From 19.05 through 63.5 | ±0.762 |
| Over 63.5 through 101.6 | ±1.270 |
| Over 101.6 through 203.2 | ±2.032 |
| Over 203.2 through 406.4 | ±2.540 |
| Over 406.4 | ±3.048 |
ASME B18.31.2 Dimensions for Tap End Reduced Body Studs (Inch)
| Nominal Size |
Diameter, D |
Minimum Nut-End Full Thread Length, Bmin |
Maximum Body Diameter, DR , for Reduced- Body Studs |
Minimum Body Diameter, DR , for Reduced- Body Studs |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| L ≤ 10 | 10 < L ≤ 16 | L > 16 | UNC and NC-5 HF Threads |
UNF Threads |
8UN Threads |
UNC and NC-5 HF Threads |
UNF Threads |
8UN Threads | ||
| ¼ | 0.2500 | 0.750 | 1.000 | 1.500 | 0.241 | 0.243 | … | 0.213 | 0.223 | … |
| 5/16 | 0.3125 | 0.875 | 1.125 | 1.625 | 0.303 | 0.304 | … | 0.271 | 0.281 | … |
| 3/8 | 0.3750 | 1.000 | 1.250 | 1.750 | 0.364 | 0.367 | … | 0.329 | 0.343 | … |
| 7/16 | 0.4375 | 1.125 | 1.375 | 1.875 | 0.426 | 0.428 | … | 0.385 | 0.4 | … |
| ½ | 0.5000 | 1.250 | 1.500 | 2.000 | 0.488 | 0.491 | … | 0.444 | 0.462 | … |
| 9/16 | 0.5625 | 1.375 | 1.625 | 2.125 | 0.550 | 0.552 | … | 0.502 | 0.521 | … |
| 5/8 | 0.6250 | 1.500 | 1.750 | 2.250 | 0.611 | 0.615 | … | 0.559 | 0.583 | … |
| ¾ | 0.7500 | 1.750 | 2.000 | 2.500 | 0.735 | 0.739 | … | 0.677 | 0.703 | … |
| 7/8 | 0.8750 | 2.000 | 2.250 | 2.750 | 0.859 | 0.863 | … | 0.795 | 0.822 | … |
| 1 | 1.0000 | 2.250 | 2.500 | 3.000 | 0.983 | 0.987 | … | 0.91 | 0.938 | … |
| 1⅛ | 1.1250 | 2.500 | 2.750 | 3.250 | 1.106 | 1.112 | 1.108 | 1.023 | 1.063 | 1.035 |
| 1¼ | 1.2500 | 2.750 | 3.000 | 3.500 | 1.231 | 1.237 | 1.233 | 1.148 | 1.188 | 1.16 |
| 1⅜ | 1.3750 | 3.000 | 3.250 | 3.750 | 1.354 | 1.362 | 1.358 | 1.256 | 1.313 | 1.284 |
| 1½ | 1.5000 | 3.250 | 3.500 | 4.000 | 1.479 | 1.487 | 1.483 | 1.381 | 1.438 | 1.409 |
| 1⅝ | 1.6250 | 3.500 | 3.750 | 4.250 | … | … | 1.608 | … | … | 1.534 |
| 1¾ | 1.7500 | 3.750 | 4.000 | 4.500 | 1.727 | … | 1.733 | 1.609 | … | 1.659 |
| 1⅞ | 1.8750 | 4.000 | 4.250 | 4.750 | … | … | 1.858 | … | … | 1.784 |
| 2 | 2.0000 | 4.250 | 4.500 | 5.000 | 1.975 | … | 1.983 | 1.843 | … | 1.909 |
| 2¼ | 2.2500 | 4.750 | 5.000 | 5.500 | 2.225 | … | 2.233 | 2.093 | … | 2.158 |
| 2½ | 2.5000 | 5.250 | 5.500 | 6.000 | 2.473 | … | 2.483 | 2.324 | … | 2.408 |
| 2¾ | 2.7500 | 5.750 | 6.000 | 6.500 | 2.723 | … | 2.733 | 2.574 | … | 2.658 |
| 3 | 3.0000 | … | 6.500 | 7.000 | 2.973 | … | 2.982 | 2.824 | … | 2.908 |
| 3¼ | 3.2500 | … | 7.000 | 7.500 | 3.223 | … | 3.232 | 3.073 | … | 3.158 |
| 3½ | 3.5000 | … | 7.500 | 8.000 | 3.473 | … | 3.482 | 3.323 | … | 3.407 |
| 3¾ | 3.7500 | … | 8.000 | 8.500 | 3.723 | … | 3.732 | 3.573 | … | 3.657 |
| 4 | 4.0000 | … | 8.500 | 9.000 | 3.973 | … | 3.982 | 3.823 | … | 3.907 |
ASME B18.31.2 Tap End Reduced Body Studs Length Tolerances (Inch)
| Range, LT | Tap-End Reduced Body Studs Tolerance |
|---|---|
| From 3/4 through 2 1/2 | ±0.03 |
| Over 2 1/2 through 4 | ±0.05 |
| Over 4 through 8 | ±0.08 |
| Over 8 through 16 | ±0.10 |
| Over 16 | ±0.12 |