Table 3. Standard Series and Selected Combinations—Unified Screw Threads Table 3. (Continued) Standard Series and Selected Combinations—Unified Screw Threads
External b
Internal b
Nominal Size, Threads per Inch, and Series Designation a
Major Diameter
UNR Minor Dia., c Max (Ref.)
Major Diameter
Pitch Diameter
Minor Diameter
Pitch Diameter
Allow ance
Max d
Min e
Max d
Class
Min
Min
Min
Max
Min
Max
Min 3.8750 3.8750 3.8750 3.8750 3.8750 3.8750 3.8750 3.8750 4.0000 4.0000 4.0000 4.0000 4.0000 4.0000 4.0000 4.0000 4.0000 4.0000 4.0000 4.0000 4.0000 4.2500 4.2500 4.2500 4.2500 4.2500 4.2500 4.5000
Class
2A 0.0030 3.8720 3.8538 3A 0.0000 3.8750 3.8568 2A 0.0027 3.8723 3.8573 3A 0.0000 3.8750 3.8600 2A 0.0020 3.8730 3.8616 3A 0.0000 3.8750 3.8636 2A 0.0018 3.8732 3.8638 3A 0.0000 3.8750 3.8656 1A 0.0034 3.9966 3.9609 3A 0.0000 4.0000 3.9762 2A 0.0030 3.9970 3.9788 3A 0.0000 4.0000 3.9818 3A 0.0000 4.0000 3.9850 2A 0.0021 3.9979 3.9850 2A 0.0020 3.9980 3.9866 3A 0.0000 4.0000 3.9886 2A 0.0018 3.9982 3.9879 2A 0.0018 3.9982 3.9888 3A 0.0000 4.0000 3.9906 2A 0.0021 4.2479 4.2350 2A 0.0020 4.2480 4.2366 3A 0.0000 4.2500 4.2386 2A 0.0019 4.2481 4.2378 2A 0.0018 4.2482 4.2388 3A 0.0000 4.2500 4.2406 2A 0.0021 4.4979 4.4850
— 3.7637 3.7538 — 3.7667 3.7593 — 3.7911 3.7820 — 3.7938 3.7870 — 3.8189 3.8124 — 3.8209 3.8160 — 3.8326 3.8268 — 3.8344 3.8300 — 3.8342 3.8172 — 3.8376 3.8291 — 3.8887 3.8788 — 3.8917 3.8843 — 3.9188 3.9120 — 3.9329 3.9259 — 3.9439 3.9374 — 3.9459 3.9410 — 3.9518 3.9456 — 3.9576 3.9517 — 3.9594 3.9550 — 4.1829 4.1758 — 4.1939 4.1873 — 4.1959 4.1910 — 4.2017 4.1955 — 4.2076 4.2017 — 4.2094 4.2050 — 4.4329 4.4258
3.6735 3.6765 3.7235 3.7262 3.7738 3.7758 3.7988 3.8006 3.6989 3.6989 3.7023 3.7985 3.8015 3.8485 3.8512 3.8788 3.8988 3.9008 3.9131 3.9238 3.9256 4.1288 4.1488 4.1508 4.1630 4.1738 4.1756 4.3788
2B 3.695
3.725
3.7667 3.7795 3.7667 3.7763 3.7938 3.8056 3.7938 3.8026 3.8209 3.8294 3.8209 3.8273 3.8344 3.8420 3.8344 3.8401 3.8376 3.8597 3.8376 3.8523 3.8376 3.8487 3.8917 3.9046 3.8917 3.9014 3.9188 3.9307 3.9188 3.9277 3.9350 3.9441 3.9459 3.9544 3.9459 3.9523 3.9536 3.9616 3.9594 3.9670 3.9594 3.9651 4.1850 4.1942 4.1959 4.2045 4.1959 4.2023 4.2036 4.2117 4.2094 4.2171 4.2094 4.2152 4.4350 4.4443
3 7 ∕ 8 -6 UN
3B 3.6950 3.7146
2B 3.740
3.765
3 7 ∕ 8 -8 UN
3B 3.7400 3.7547
2B 3.785
3.803
3 7 ∕ 8 -12 UN
3B 3.7850 3.7948
2B 3.807
3.821
3 7 ∕ 8 -16 UN
3B 3.8070 3.8159
4-4 UNC
1B 3.729 2B 3.729
3.767 3.767
2A 0.0034 3.9966 3.9728 3.9609 3.8342 3.8229
3B 3.7290 3.7594
4-6 UN
2B 3.820
3.850
3B 3.8200 3.8396
4-8 UN
2A 0.0027 3.9973 3.9823 3.9748 3.9161 3.9070
2B 3.865
3.890
3B 3.8650 3.8797
4-10 UNS 4-12 UN 4-14 UNS 4-16 UN
2B 3.892 2B 3.910 2B 3.923 2B 3.932 2B 4.142 2B 4.160 2B 4.173 2B 4.182
3.913 3.928 3.938 3.946 4.163 4.178 4.188 4.196
3B 3.9100 3.9198
3B 3.9320 3.9409
4 1 ∕ 4 -10 UNS 4 1 ∕ 4 -12 UN 4 1 ∕ 4 -14 UNS 4 1 ∕ 4 -16 UN
3B 4.1600 4.1698
3B 4.1820 4.1909
4.413
4 1 ∕ 2 -10 UNS
2B 4.392
Made with FlippingBook - Share PDF online