ASME B18.31.2 Clamping Type Reduced Body Studs
ASME B18.31.2 Dimensions for Clamping Type Reduced Body Studs (mm)
| Nominal Size |
Diameter, D | Umax = 2 Thread Pitches | Maximum Body Diameter, DR , for Reduced-Body Studs | Minimum Body Diameter, DR , for Reduced-Body Studs | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| UNC Threads | UNF Threads | 8UN Threads | UNC and NC-5 HF Threads |
UNF Threads |
8UN Threads | UNC and NC-5 HF Threads |
UNF Threads |
8UN Threads | ||
| ¼ | 6.350 | 2.540 | 1.803 | ... | 6.121 | 6.172 | … | 5.410 | 5.664 | … |
| 5/16 | 7.938 | 2.819 | 2.108 | ... | 7.696 | 7.722 | … | 6.883 | 7.137 | … |
| 3/8 | 9.525 | 3.175 | 2.108 | ... | 9.246 | 9.322 | … | 8.357 | 8.712 | … |
| 7/16 | 11.113 | 3.632 | 2.540 | ... | 10.820 | 10.871 | … | 9.779 | 10.160 | … |
| ½ | 12.700 | 3.912 | 2.540 | ... | 12.395 | 12.471 | … | 11.278 | 11.735 | … |
| 9/16 | 14.288 | 4.242 | 2.819 | ... | 13.970 | 14.021 | … | 12.751 | 13.233 | … |
| 5/8 | 15.875 | 4.623 | 2.819 | ... | 15.519 | 15.621 | … | 14.199 | 14.808 | … |
| ¾ | 19.050 | 5.080 | 3.175 | ... | 18.669 | 18.771 | … | 17.196 | 17.856 | … |
| 7/8 | 22.225 | 5.639 | 3.632 | ... | 21.819 | 21.920 | … | 20.193 | 20.879 | … |
| 1 | 25.400 | 6.350 | 4.242 | ... | 24.968 | 25.070 | … | 23.114 | 23.825 | … |
| 1⅛ | 28.575 | 7.264 | 4.242 | 6.350 | 28.092 | 28.245 | 28.143 | 25.984 | 27.000 | 26.289 |
| 1¼ | 31.750 | 7.264 | 4.242 | 6.350 | 31.267 | 31.420 | 31.318 | 29.159 | 30.175 | 29.464 |
| 1⅜ | 34.925 | 8.458 | 4.242 | 6.350 | 34.392 | 34.595 | 34.493 | 31.902 | 33.350 | 32.614 |
| 1½ | 38.100 | 8.458 | 4.242 | 6.350 | 37.567 | 37.770 | 37.668 | 35.077 | 36.525 | 35.789 |
| 1⅝ | 41.275 | ... | ... | 6.350 | … | … | 40.843 | … | … | 38.964 |
| 1¾ | 44.450 | 10.160 | ... | 6.350 | 43.866 | … | 44.018 | 40.869 | … | 42.139 |
| 1⅞ | 47.625 | ... | ... | 6.350 | … | … | 47.193 | … | … | 45.314 |
| 2 | 50.800 | 11.278 | ... | 6.350 | 50.165 | … | 50.368 | 46.812 | … | 48.489 |
| 2¼ | 57.150 | 11.278 | ... | 6.350 | 56.515 | … | 56.718 | 53.162 | … | 54.813 |
| 2½ | 63.500 | 12.700 | ... | 6.350 | 62.814 | … | 63.068 | 59.030 | … | 61.163 |
| 2¾ | 69.850 | 12.700 | ... | 6.350 | 69.164 | … | 69.418 | 65.380 | … | 67.513 |
| 3 | 76.200 | 12.700 | ... | 6.350 | 75.514 | … | 75.743 | 71.730 | … | 73.863 |
| 3¼ | 82.550 | 12.700 | ... | 6.350 | 81.864 | … | 82.093 | 78.054 | … | 80.213 |
| 3½ | 88.900 | 12.700 | ... | 6.350 | 88.214 | … | 88.443 | 84.404 | … | 86.538 |
| 3¾ | 95.250 | 12.700 | ... | 6.350 | 90.754 | … | 92.888 | 94.564 | … | 94.793 |
| 4 | 101.600 | 12.700 | ... | 6.350 | 97.104 | … | 99.238 | 100.914 | … | 101.143 |
ASME B18.31.2 Clamping Type Reduced Body Studs Length Tolerances (mm)
| Range, LT | Tolerances |
|---|---|
| From 19.05 through 63.5 | ±1.016 |
| Over 63.5 through 101.6 | ±2.032 |
| Over 101.6 through 203.2 | ±2.540 |
| Over 203.2 through 406.4 | ±3.048 |
| Over 406.4 | ±4.572 |
ASME B18.31.2 Dimensions for Clamping Type Reduced Body Studs (Inch)
| Nominal Size |
Diameter, D |
Umax = 2 Thread Pitches | Maximum Body Diameter, DR , for Reduced- Body Studs |
Minimum Body Diameter, DR , for Reduced- Body Studs |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| UNC Threads | UNF Threads | 8UN Threads | UNC and NC-5 HF Threads |
UNF Threads |
8UN Threads | UNC and NC-5 HF Threads |
UNF Threads |
8UN Threads | ||
| ¼ | 0.2500 | 0.100 | 0.071 | ... | 0.241 | 0.243 | … | 0.213 | 0.223 | … |
| 5/16 | 0.3125 | 0.111 | 0.083 | ... | 0.303 | 0.304 | … | 0.271 | 0.281 | … |
| 3/8 | 0.3750 | 0.125 | 0.083 | ... | 0.364 | 0.367 | … | 0.329 | 0.343 | … |
| 7/16 | 0.4375 | 0.143 | 0.100 | ... | 0.426 | 0.428 | … | 0.385 | 0.4 | … |
| ½ | 0.5000 | 0.154 | 0.100 | ... | 0.488 | 0.491 | … | 0.444 | 0.462 | … |
| 9/16 | 0.5625 | 0.167 | 0.111 | ... | 0.550 | 0.552 | … | 0.502 | 0.521 | … |
| 5/8 | 0.6250 | 0.182 | 0.111 | ... | 0.611 | 0.615 | … | 0.559 | 0.583 | … |
| ¾ | 0.7500 | 0.200 | 0.125 | ... | 0.735 | 0.739 | … | 0.677 | 0.703 | … |
| 7/8 | 0.8750 | 0.222 | 0.143 | ... | 0.859 | 0.863 | … | 0.795 | 0.822 | … |
| 1 | 1.0000 | 0.250 | 0.167 | ... | 0.983 | 0.987 | … | 0.91 | 0.938 | … |
| 1⅛ | 1.1250 | 0.286 | 0.167 | 0.250 | 1.106 | 1.112 | 1.108 | 1.023 | 1.063 | 1.035 |
| 1¼ | 1.2500 | 0.286 | 0.167 | 0.250 | 1.231 | 1.237 | 1.233 | 1.148 | 1.188 | 1.16 |
| 1⅜ | 1.3750 | 0.333 | 0.167 | 0.250 | 1.354 | 1.362 | 1.358 | 1.256 | 1.313 | 1.284 |
| 1½ | 1.5000 | 0.333 | 0.167 | 0.250 | 1.479 | 1.487 | 1.483 | 1.381 | 1.438 | 1.409 |
| 1⅝ | 1.6250 | ... | ... | 0.250 | … | … | 1.608 | … | … | 1.534 |
| 1¾ | 1.7500 | 0.400 | ... | 0.250 | 1.727 | … | 1.733 | 1.609 | … | 1.659 |
| 1⅞ | 1.8750 | ... | ... | 0.250 | … | … | 1.858 | … | … | 1.784 |
| 2 | 2.0000 | 0.444 | ... | 0.250 | 1.975 | … | 1.983 | 1.843 | … | 1.909 |
| 2¼ | 2.2500 | 0.444 | ... | 0.250 | 2.225 | … | 2.233 | 2.093 | … | 2.158 |
| 2½ | 2.5000 | 0.500 | ... | 0.250 | 2.473 | … | 2.483 | 2.324 | … | 2.408 |
| 2¾ | 2.7500 | 0.500 | ... | 0.250 | 2.723 | … | 2.733 | 2.574 | … | 2.658 |
| 3 | 3.0000 | 0.500 | ... | 0.250 | 2.973 | … | 2.982 | 2.824 | … | 2.908 |
| 3¼ | 3.2500 | 0.500 | ... | 0.250 | 3.223 | … | 3.232 | 3.073 | … | 3.158 |
| 3½ | 3.5000 | 0.500 | ... | 0.250 | 3.473 | … | 3.482 | 3.323 | … | 3.407 |
| 3¾ | 3.7500 | 0.500 | ... | 0.250 | 3.573 | … | 3.657 | 3.723 | … | 3.732 |
| 4 | 4.0000 | 0.500 | ... | 0.250 | 3.823 | … | 3.907 | 3.973 | … | 3.982 |
ASME B18.31.2 Clamping Type Reduced Body Studs Length Tolerances
| Range, LT | Tolerances |
|---|---|
| From ¾ through 2½ | ±0.04 |
| Over 2½ through 4 | ±0.08 |
| Over 4 through 8 | ±0.10 |
| Over 8 through 16 | ±0.12 |
| Over 16 | ±0.18 |