Threads and Threading - Sportpilot.info

Machinery's Handbook 27th Edition
Table 3. (Continued) Standard Series and Selected Combinations — Unified Screw Threads
Nominal Size,
Threads per Inch,
and Series
Designation
5
⁄8 –32 UN 2A 0.0011 0.6239 0.6179 — 0.6036 0.6000 0.5867 2B 0.591 0.599 0.6047 0.6093 0.6250
a
Externalb Internalb Allow-
Major Diameter Pitch Diameter
UNR Minor
Dia.,
Class ance
c Max
Minor Diameter Pitch Diameter
Major
Diameter
Max (Ref.) Class
d Min Mine Maxd Min Min Max Min Max Min
3A 0.0000 0.6250 0.6190 — 0.6047 0.6020 0.5878 3B 0.5910 0.5969 0.6047 0.6082 0.6250
11 ⁄16 –12 UN 2A 0.0016 0.6859 0.6745 — 0.6318 0.6264 0.5867 2B 0.597 0.615 0.6334 0.6405 0.6875
3A 0.0000 0.6875 0.6761 — 0.6334 0.6293 0.5883 3B 0.5970 0.6085 0.6334 0.6387 0.6875
11 ⁄16 –16 UN 2A 0.0014 0.6861 0.6767 — 0.6455 0.6407 0.6116 2B 0.620 0.634 0.6469 0.6531 0.6875
3A 0.0000 0.6875 0.6781 — 0.6469 0.6433 0.6130 3B 0.6200 0.6284 0.6469 0.6515 0.6875
11 ⁄16–20 UN 2A 0.0013 0.6862 0.6781 — 0.6537 0.6494 0.6267 2B 0.633 0.645 0.6550 0.6606 0.6875
3A 0.0000 0.6875 0.6794 — 0.6550 0.6518 0.6280 3B 0.6330 0.6412 0.6550 0.6592 0.6875
11 ⁄16 –24 UNEF 2A 0.0012 0.6863 0.6791 — 0.6592 0.6552 0.6367 2B 0.642 0.652 0.6604 0.6656 0.6875
3A 0.0000 0.6875 0.6803 — 0.6604 0.6574 0.6379 3B 0.6420 0.6494 0.6604 0.6643 0.6875
11 ⁄16 –28 UN 2A 0.0011 0.6864 0.6799 — 0.6632 0.6594 0.6438 2B 0.649 0.657 0.6643 0.6692 0.6875
3A 0.0000 0.6875 0.6810 — 0.6643 0.6615 0.6449 3B 0.6490 0.6551 0.6643 0.6680 0.6875
11 ⁄16 –32 UN 2A 0.0011 0.6864 0.6804 — 0.6661 0.6625 0.6492 2B 0.654 0.661 0.6672 0.6718 0.6875
3A 0.0000 0.6875 0.6815 — 0.6672 0.6645 0.6503 3B 0.6540 0.6594 0.6672 0.6707 0.6875
3 ⁄4 –10 UNC 1A 0.0018 0.7482 0.7288 — 0.6832 0.6744 0.6291 1B 0.642 0.663 0.6850 0.6965 0.7500
2A 0.0018 0.7482 0.7353 0.7288 0.6832 0.6773 0.6291 2B 0.642 0.663 0.6850 0.6927 0.7500
3A 0.0000 0.7500 0.7371 — 0.6850 0.6806 0.6309 3B 0.6420 0.6545 0.6850 0.6907 0.7500
3
⁄4 –12 UN 2A 0.0017 0.7483 0.7369 — 0.6942 0.6887 0.6491 2B 0.660 0.678 0.6959 0.7031 0.7500
3A 0.0000 0.7500 0.7386 — 0.6959 0.6918 0.6508 3B 0.6600 0.6707 0.6959 0.7013 0.7500
3
⁄4 –14 UNS 2A 0.0015 0.7485 0.7382 — 0.7021 0.6970 0.6635 2B 0.673 0.688 0.7036 0.7103 0.7500
3 ⁄4–16 UNF 1A 0.0015 0.7485 0.7343 — 0.7079 0.7004 0.6740 1B 0.682 0.696 0.7094 0.7192 0.7500
2A 0.0015 0.7485 0.7391 — 0.7079 0.7029 0.6740 2B 0.682 0.696 0.7094 0.7159 0.7500
3A 0.0000 0.7500 0.7406 — 0.7094 0.7056 0.6755 3B 0.6820 0.6908 0.7094 0.7143 0.7500
3
⁄4 –18 UNS 2A 0.0014 0.7486 0.7399 — 0.7125 0.7079 0.6825 2B 0.690 0.703 0.7139 0.7199 0.7500
3
⁄4 –20 UNEF 2A 0.0013 0.7487 0.7406 — 0.7162 0.7118 0.6892 2B 0.696 0.707 0.7175 0.7232 0.7500
3A 0.0000 0.7500 0.7419 — 0.7175 0.7142 0.6905 3B 0.6960 0.7037 0.7175 0.7218 0.7500
3
⁄4 –24 UNS 2A 0.0012 0.7488 0.7416 — 0.7217 0.7176 0.6992 2B 0.705 0.715 0.7229 0.7282 0.7500
3
⁄4 –24 UNS 2A 0.0012 0.7488 0.7421 — 0.7247 0.7208 0.7047 2B 0.710 0.719 0.7259 0.7310 0.7500
Copyright 2004, Industrial Press, Inc., New York, NY
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UNIFIED SCREW THREADS