Threads and Threading - Sportpilot.info

Nominal Size,
Threads per Inch,
and Series
Designation a
Class
Table 3. (Continued) Standard Series and Selected Combinations — Unified Screw Threads
Allowance
Machinery's Handbook 27th Edition
Externalb Internalb Major Diameter Pitch Diameter
UNR Minor
Dia., c Max
Minor Diameter Pitch Diameter
Major
Diameter
Max (Ref.) Class
d Min Mine Maxd Min Min Max Min Max Min
4 1 ⁄ 2 –12 UN 2A 0.0020 4.4980 4.4866 — 4.4439 4.4374 4.3988 2B 4.410 4.428 4.4459 4.4544 4.5000
3A 0.0000 4.5000 4.4886 — 4.4459 4.4410 4.4008 3B 4.4100 4.4198 4.4459 4.4523 4.5000
4 1 ⁄ 2 –16 UN 2A 0.0018 4.4982 4.4888 — 4.4576 4.4517 4.4237 2B 4.432 4.446 4.4594 4.4670 4.5000
3A 0.0000 4.5000 4.4906 — 4.4594 4.4550 4.4255 3B 4.4320 4.4408 4.4594 4.4651 4.5000
4 3 ⁄ 4 –10 UNS 2A 0.0022 4.7478 4.7349 — 4.6828 4.6756 4.6288 2B 4.642 4.663 4.6850 4.6944 4.7500
4 3 ⁄ 4–14 UNS 2A 0.0019 4.7481 4.7378 — 4.7017 4.6953 4.6631 2B 4.673 4.688 4.7036 4.7119 4.7500
43 ⁄ 4 –12 UN 2A 0.0020 4.7480 4.7366 — 4.6939 4.6872 4.6488 2B 4.660 4.678 4.6959 4.7046 4.7500
3A 0.0000 4.7500 4.7386 — 4.6959 4.6909 4.6508 3B 4.6600 4.6698 4.6959 4.7025 4.7500
43 ⁄ 4 –16 UN 2A 0.0018 4.7482 4.7388 — 4.7076 4.7015 4.6737 2B 4.682 4.696 4.7094 4.7173 4.7500
3A 0.0000 4.7500 4.7406 — 4.7094 4.7049 4.6755 3B 4.6820 4.6908 4.7094 4.7153 4.7500
5.00–10 UNS 2A 0.0022 4.9978 4.9849 — 4.9328 4.9256 4.8788 2B 4.892 4.913 4.9350 4.9444 5.0000
5.00–14 UNS 2A 0.0019 4.9981 4.9878 — 4.9517 4.9453 4.9131 2B 4.923 4.938 4.9536 4.9619 5.0000
5.00–12 UN 2A 0.0020 4.9980 4.9866 — 4.9439 4.9372 4.8988 2B 4.910 4.928 4.9459 4.9546 5.0000
3A 0.0000 5.0000 4.9886 — 4.9459 4.9409 4.9008 3B 4.9100 4.9198 4.9459 4.9525 5.0000
5.00–16 UN 2A 0.0018 4.9982 4.9888 — 4.9576 4.9515 4.9237 2B 4.932 4.946 4.9594 4.9673 5.0000
3A 0.0000 5.0000 4.9906 — 4.9594 4.9549 4.9255 3B 4.9320 4.9408 4.9594 4.9653 5.0000
51 ⁄ 4 –10 UNS 2A 0.0022 5.2478 5.2349 — 5.1829 5.1756 5.1288 2B 5.142 5.163 5.1850 5.1944 5.2500
51 ⁄ 4 –14 UNS 2A 0.0019 5.2481 5.2378 — 5.2017 5.1953 5.1631 2B 5.173 5.188 5.2036 5.2119 5.2500
51 ⁄ 4 –12 UN 2A 0.0020 5.2480 5.2366 — 5.1939 5.1872 5.1488 2B 5.160 5.178 5.1959 5.2046 5.2500
3A 0.0000 5.2500 5.2386 — 5.1959 5.1909 5.1508 3B 5.1600 5.1698 5.1959 5.2025 5.2500
51 ⁄ 4 –16 UN 2A 0.0018 5.2482 5.2388 — 5.2076 5.2015 5.1737 2B 5.182 5.196 5.2094 5.2173 5.2500
3A 0.0000 5.2500 5.2406 — 5.2094 5.2049 5.1755 3B 5.1820 5.1908 5.2094 5.2153 5.2500
51 ⁄ 2–10 UNS 2A 0.0022 5.4978 5.4849 — 5.4328 5.4256 5.3788 2B 5.392 5.413 5.4350 5.4444 5.5000
51 ⁄ 2 –14 UNS 2A 0.0019 5.4981 5.4878 — 5.4517 5.4453 5.4131 2B 5.423 5.438 5.4536 5.4619 5.5000
51 ⁄ 2 –12 UN 2A 0.0020 5.4980 5.4866 — 5.4439 5.4372 5.3988 2B 5.410 5.428 5.4459 5.4546 5.5000
3A 0.0000 5.5000 5.4886 — 5.4459 5.4409 5.4008 3B 5.4100 5.4198 5.4459 5.4525 5.5000
51 ⁄ 2 –16 UN 2A 0.0018 5.4982 5.4888 — 5.4576 5.4515 5.4237 2B 5.432 5.446 5.4594 5.4673 5.5000
3A 0.0000 5.5000 5.4906 — 5.4594 5.4549 5.4255 3B 5.4320 5.4408 5.4594 5.4653 5.5000
Copyright 2004, Industrial Press, Inc., New York, NY
UNIFIED SCREW THREADS 1761