Machinery''''s Handbook 27th Episode 3 Part 3 pps

UNIFIED SCREW THREADS 1755 2 3 ⁄ 8 –20 UN 2A 0.0015 2.3735 2.3654 — 2.3410 2.3359 2.3140 2B 2.321 2.332 2.3425 2.3491 2.3750 3A 0.0000 2.3750 2.3669 — 2.3425 2.3387 2.3155 3B 2.3210 2.3287 2.3425 2.3475 2.3750 2 7 ⁄ 16 –16 UNS 2A 0.0017 2.4358 2.4264 — 2.3952 2.3897 2.3613 2B 2.370 2.384 2.3969 2.4041 2.4375 3A 0.0000 2.4375 2.4281 — 2.3969 2.3928 2.3630 3B 2.3700 2.3783 2.3969 2.4023 2.4375 2 1 ⁄ 2 –4 UNC 1A 0.0031 2.4969 2.4612 — 2.3345 2.3190 2.1992 1B 2.229 2.267 2.3376 2.3578 2.5000 2A 0.0031 2.4969 2.4731 2.4612 2.3345 2.3241 2.1992 2B 2.229 2.267 2.3376 2.3511 2.5000 3A 0.0000 2.5000 2.4762 — 2.3376 2.3298 2.2023 3B 2.2290 2.2594 2.3376 2.3477 2.5000 2 1 ⁄ 2 –6 UN 2A 0.0027 2.4973 2.4791 — 2.3890 2.3800 2.2989 2B 2.320 2.350 2.3917 2.4033 2.5000 3A 0.0000 2.5000 2.4818 — 2.3917 2.3850 2.3016 3B 2.3200 2.3396 2.3917 2.4004 2.5000 2 1 ⁄ 2 –8 UN 2A 0.0024 2.4976 2.4826 2.4751 2.4164 2.4082 2.3488 2B 2.365 2.390 2.4188 2.4294 2.5000 3A 0.0000 2.5000 2.4850 — 2.4188 2.4127 2.3512 3B 2.3650 2.3797 2.4188 2.4268 2.5000 2 1 ⁄ 2 –10 UNS 2A 0.0020 2.4980 2.4851 — 2.4330 2.4263 2.3790 2B 2.392 2.413 2.4350 2.4437 2.5000 2 1 ⁄ 2 –12 UN 2A 0.0019 2.4981 2.4867 — 2.4440 2.4378 2.3989 2B 2.410 2.428 2.4459 2.4540 2.5000 3A 0.0000 2.5000 2.4886 — 2.4459 2.4413 2.4008 3B 2.4100 2.4198 2.4459 2.4519 2.5000 2 1 ⁄ 2 –14 UNS 2A 0.0017 2.4983 2.4880 — 2.4519 2.4461 2.4133 2B 2.423 2.438 2.4536 2.4612 2.5000 2 1 ⁄ 2 –16 UN 2A 0.0017 2.4983 2.4889 — 2.4577 2.4522 2.4238 2B 2.432 2.446 2.4594 2.4666 2.5000 3A 0.0000 2.5000 2.4906 — 2.4594 2.4553 2.4255 3B 2.4320 2.4408 2.4594 2.4648 2.5000 2 1 ⁄ 2 –18 UNS 2A 0.0016 2.4984 2.4897 — 2.4623 2.4570 2.4323 2B 2.440 2.453 2.4639 2.4708 2.5000 2 1 ⁄ 2 –20 UN 2A 0.0015 2.4985 2.4904 — 2.4660 2.4609 2.4390 2B 2.446 2.457 2.4675 2.4741 2.5000 3A 0.0000 2.5000 2.4919 — 2.4675 2.4637 2.4405 3B 2.4460 2.4537 2.4675 2.4725 2.5000 2 5 ⁄ 8 –6 UN 2A 0.0027 2.6223 2.6041 — 2.5140 2.5050 2.4239 2B 2.445 2.475 2.5167 2.5285 2.6250 3A 0.0000 2.6250 2.6068 — 2.5167 2.5099 2.4266 3B 2.4450 2.4646 2.5167 2.5255 2.6250 2 5 ⁄ 8 –8 UN 2A 0.0025 2.6225 2.6075 — 2.5413 2.5331 2.4737 2B 2.490 2.515 2.5438 2.5545 2.6250 3A 0.0000 2.6250 2.6100 — 2.5438 2.5376 2.4762 3B 2.4900 2.5047 2.5438 2.5518 2.6250 2 5 ⁄ 8 –12 UN 2A 0.0019 2.6231 2.6117 — 2.5690 2.5628 2.5239 2B 2.535 2.553 2.5709 2.5790 2.6250 3A 0.0000 2.6250 2.6136 — 2.5709 2.5663 2.5258 3B 2.5350 2.5448 2.5709 2.5769 2.6250 2 5 ⁄ 8 –16 UN 2A 0.0017 2.6233 2.6139 — 2.5827 2.5772 2.5488 2B 2.557 2.571 2.5844 2.5916 2.6250 3A 0.0000 2.6250 2.6156 — 2.5844 2.5803 2.5505 3B 2.5570 2.5658 2.5844 2.5898 2.6250 Table 3. (Continued) Standard Series and Selected Combinations — Unified Screw Threads Nominal Size, Threads per Inch, and Series Designation a External b Internal b Class Allow- ance Major Diameter Pitch Diameter UNR Minor Dia., c Max (Ref.) Class Minor Diameter Pitch Diameter Major Diameter Max d Min Min e Max d Min Min Max Min Max Min Machinery's Handbook 27th Edition Copyright 2004, Industrial Press, Inc., New York, NY UNIFIED SCREW THREADS1756 2 5 ⁄ 8 –20 UN 2A 0.0015 2.6235 2.6154 — 2.5910 2.5859 2.5640 2B 2.571 2.582 2.5925 2.5991 2.6250 3A 0.0000 2.6250 2.6169 — 2.5925 2.5887 2.5655 3B 2.5710 2.5787 2.5925 2.5975 2.6250 2 3 ⁄ 4 –4 UNC 1A 0.0032 2.7468 2.7111 — 2.5844 2.5686 2.4491 1B 2.479 2.517 2.5876 2.6082 2.7500 2A 0.0032 2.7468 2.7230 2.7111 2.5844 2.5739 2.4491 2B 2.479 2.517 2.5876 2.6013 2.7500 3A 0.0000 2.7500 2.7262 — 2.5876 2.5797 2.4523 3B 2.4790 2.5094 2.5876 2.5979 2.7500 2 3 ⁄ 4 –6 UN 2A 0.0027 2.7473 2.7291 — 2.6390 2.6299 2.5489 2B 2.570 2.600 2.6417 2.6536 2.7500 3A 0.0000 2.7500 2.7318 — 2.6417 2.6349 2.5516 3B 2.5700 2.5896 2.6417 2.6506 2.7500 2 3 ⁄ 4 –8 UN 2A 0.0025 2.7475 2.7325 2.7250 2.6663 2.6580 2.5987 2B 2.615 2.640 2.6688 2.6796 2.7500 3A 0.0000 2.7500 2.7350 — 2.6688 2.6625 2.6012 3B 2.6150 2.6297 2.6688 2.6769 2.7500 2 3 ⁄ 4 –10 UNS 2A 0.0020 2.7480 2.7351 — 2.6830 2.6763 2.6290 2B 2.642 2.663 2.6850 2.6937 2.7500 2 3 ⁄ 4 –12 UN 2A 0.0019 2.7481 2.7367 — 2.6940 2.6878 2.6489 2B 2.660 2.678 2.6959 2.7040 2.7500 3A 0.0000 2.7500 2.7386 — 2.6959 2.6913 2.6508 3B 2.6600 2.6698 2.6959 2.7019 2.7500 2 3 ⁄ 4 –14 UNS 2A 0.0017 2.7483 2.7380 — 2.7019 2.6961 2.6633 2B 2.673 2.688 2.7036 2.7112 2.7500 2 3 ⁄ 4 –16 UN 2A 0.0017 2.7483 2.7389 — 2.7077 2.7022 2.6738 2B 2.682 2.696 2.7094 2.7166 2.7500 3A 0.0000 2.7500 2.7406 — 2.7094 2.7053 2.6755 3B 2.6820 2.6908 2.7094 2.7148 2.7500 2 3 ⁄ 4 –18 UNS 2A 0.0016 2.7484 2.7397 — 2.7123 2.7070 2.6823 2B 2.690 2.703 2.7139 2.7208 2.7500 2 3 ⁄ 4 –20 UN 2A 0.0015 2.7485 2.7404 — 2.7160 2.7109 2.6890 2B 2.696 2.707 2.7175 2.7241 2.7500 3A 0.0000 2.7500 2.7419 — 2.7175 2.7137 2.6905 3B 2.6960 2.7037 2.7175 2.7225 2.7500 2 7 ⁄ 8 –6 UN 2A 0.0028 2.8722 2.8540 — 2.7639 2.7547 2.6738 2B 2.695 2.725 2.7667 2.7787 2.8750 3A 0.0000 2.8750 2.8568 — 2.7667 2.7598 2.6766 3B 2.6950 2.7146 2.7667 2.7757 2.8750 2 7 ⁄ 8 –8 UN 2A 0.0025 2.8725 2.8575 — 2.7913 2.7829 2.7237 2B 2.740 2.765 2.7938 2.8048 2.8750 3A 0.0000 2.8750 2.8600 — 2.7938 2.7875 2.7262 3B 2.7400 2.7547 2.7938 2.8020 2.8750 2 7 ⁄ 8 –12 UN 2A 0.0019 2.8731 2.8617 — 2.8190 2.8127 2.7739 2B 2.785 2.803 2.8209 2.8291 2.8750 3A 0.0000 2.8750 2.8636 — 2.8209 2.8162 2.7758 3B 2.7850 2.7948 2.8209 2.8271 2.8750 2 7 ⁄ 8 –16 UN 2A 0.0017 2.8733 2.8639 — 2.8327 2.8271 2.7988 2B 2.807 2.821 2.8344 2.8417 2.8750 3A 0.0000 2.8750 2.8656 — 2.8344 2.8302 2.8005 3B 2.8070 2.8158 2.8344 2.8399 2.8750 2 7 ⁄ 8 –20 UN 2A 0.0016 2.8734 2.8653 — 2.8409 2.8357 2.8139 2B 2.821 2.832 2.8425 2.8493 2.8750 3A 0.0000 2.8750 2.8669 — 2.8425 2.8386 2.8155 3B 2.8210 2.8287 2.8425 2.8476 2.8750 Table 3. (Continued) Standard Series and Selected Combinations — Unified Screw Threads Nominal Size, Threads per Inch, and Series Designation a External b Internal b Class Allow- ance Major Diameter Pitch Diameter UNR Minor Dia., c Max (Ref.) Class Minor Diameter Pitch Diameter Major Diameter Max d Min Min e Max d Min Min Max Min Max Min Machinery's Handbook 27th Edition Copyright 2004, Industrial Press, Inc., New York, NY UNIFIED SCREW THREADS 1757 3–4 UNC 1A 0.0032 2.9968 2.9611 — 2.8344 2.8183 2.6991 1B 2.729 2.767 2.8376 2.8585 3.0000 2A 0.0032 2.9968 2.9730 2.9611 2.8344 2.8237 2.6991 2B 2.729 2.767 2.8376 2.8515 3.0000 3A 0.0000 3.0000 2.9762 — 2.8376 2.8296 2.7023 3B 2.7290 2.7594 2.8376 2.8480 3.0000 3–6 UN 2A 0.0028 2.9972 2.9790 — 2.8889 2.8796 2.7988 2B 2.820 2.850 2.8917 2.9038 3.0000 3A 0.0000 3.0000 2.9818 — 2.8917 2.8847 2.8016 3B 2.8200 2.8396 2.8917 2.9008 3.0000 3–8 UN 2A 0.0026 2.9974 2.9824 2.9749 2.9162 2.9077 2.8486 2B 2.865 2.890 2.9188 2.9299 3.0000 3A 0.0000 3.0000 2.9850 — 2.9188 2.9124 2.8512 3B 2.8650 2.8797 2.9188 2.9271 3.0000 3–10 UNS 2A 0.0020 2.9980 2.9851 — 2.9330 2.9262 2.8790 2B 2.892 2.913 2.9350 2.9439 3.0000 3–12 UN 2A 0.0019 2.9981 2.9867 — 2.9440 2.9377 2.8989 2B 2.910 2.928 2.9459 2.9541 3.0000 3A 0.0000 3.0000 2.9886 — 2.9459 2.9412 2.9008 3B 2.9100 2.9198 2.9459 2.9521 3.0000 3–14 UNS 2A 0.0018 2.9982 2.9879 — 2.9518 2.9459 2.9132 2B 2.923 2.938 2.9536 2.9613 3.0000 3–16 UN 2A 0.0017 2.9983 2.9889 — 2.9577 2.9521 2.9238 2B 2.932 2.946 2.9594 2.9667 3.0000 3A 0.0000 3.0000 2.9906 — 2.9594 2.9552 2.9255 3B 2.9320 2.9408 2.9594 2.9649 3.0000 3–18 UNS 2A 0.0016 2.9984 2.9897 — 2.9623 2.9569 2.9323 2B 2.940 2.953 2.9639 2.9709 3.0000 3–20 UN 2A 0.0016 2.9984 2.9903 — 2.9659 2.9607 2.9389 2B 2.946 2.957 2.9675 2.9743 3.0000 3A 0.0000 3.0000 2.9919 — 2.9675 2.9636 2.9405 3B 2.9460 2.9537 2.9675 2.9726 3.0000 3 1 ⁄ 8 –6 UN 2A 0.0028 3.1222 3.1040 — 3.0139 3.0045 2.9238 2B 2.945 2.975 3.0167 3.0289 3.1250 3A 0.0000 3.1250 3.1068 — 3.0167 3.0097 2.9266 3B 2.9450 2.9646 3.0167 3.0259 3.1250 3 1 ⁄ 8 –8 UN 2A 0.0026 3.1224 3.1074 — 3.0412 3.0326 2.9736 2B 2.990 3.015 3.0438 3.0550 3.1250 3A 0.0000 3.1250 3.1100 — 3.0438 3.0374 2.9762 3B 2.9900 3.0047 3.0438 3.0522 3.1250 3 1 ⁄ 8 –12 UN 2A 0.0019 3.1231 3.1117 — 3.0690 3.0627 3.0239 2B 3.035 3.053 3.0709 3.0791 3.1250 3A 0.0000 3.1250 3.1136 — 3.0709 3.0662 3.0258 3B 3.0350 3.0448 3.0709 3.0771 3.1250 3 1 ⁄ 8 –16 UN 2A 0.0017 3.1233 3.1139 — 3.0827 3.0771 3.0488 2B 3.057 3.071 3.0844 3.0917 3.1250 3A 0.0000 3.1250 3.1156 — 3.0844 3.0802 3.0505 3B 3.0570 3.0658 3.0844 3.0899 3.1250 3 1 ⁄ 4 –4 UNC 1A 0.0033 3.2467 3.2110 — 3.0843 3.0680 2.9490 1B 2.979 3.017 3.0876 3.1088 3.2500 2A 0.0033 3.2467 3.2229 3.2110 3.0843 3.0734 2.9490 2B 2.979 3.017 3.0876 3.1017 3.2500 3A 0.0000 3.2500 3.2262 — 3.0876 3.0794 2.9523 3B 2.9790 3.0094 3.0876 3.0982 3.2500 3 1 ⁄ 4 –6 UN 2A 0.0028 3.2472 3.2290 — 3.1389 3.1294 3.0488 2B 3.070 3.100 3.1417 3.1540 3.2500 3A 0.0000 3.2500 3.2318 — 3.1417 3.1346 3.0516 3B 3.0700 3.0896 3.1417 3.1509 3.2500 Table 3. (Continued) Standard Series and Selected Combinations — Unified Screw Threads Nominal Size, Threads per Inch, and Series Designation a External b Internal b Class Allow- ance Major Diameter Pitch Diameter UNR Minor Dia., c Max (Ref.) Class Minor Diameter Pitch Diameter Major Diameter Max d Min Min e Max d Min Min Max Min Max Min Machinery's Handbook 27th Edition Copyright 2004, Industrial Press, Inc., New York, NY UNIFIED SCREW THREADS1758 3 1 ⁄ 4 –8 UN 2A 0.0026 3.2474 3.2324 3.2249 3.1662 3.1575 3.0986 2B 3.115 3.140 3.1688 3.1801 3.2500 3A 0.0000 3.2500 3.2350 — 3.1688 3.1623 3.1012 3B 3.1150 3.1297 3.1688 3.1773 3.2500 3 1 ⁄ 4 –10 UNS 2A 0.0020 3.2480 3.2351 — 3.1830 3.1762 3.1290 2B 3.142 3.163 3.1850 3.1939 3.2500 3 1 ⁄ 4 –12 UN 2A 0.0019 3.2481 3.2367 — 3.1940 3.1877 3.1489 2B 3.160 3.178 3.1959 3.2041 3.2500 3A 0.0000 3.2500 3.2386 — 3.1959 3.1912 3.1508 3B 3.1600 3.1698 3.1959 3.2041 3.2500 3 1 ⁄ 4 –14 UNS 2A 0.0018 3.2482 3.2379 — 3.2018 3.1959 3.1632 2B 3.173 3.188 3.2036 3.2113 3.2500 3 1 ⁄ 4 –16 UN 2A 0.0017 3.2483 3.2389 — 3.2077 3.2021 3.1738 2B 3.182 3.196 3.2094 3.2167 3.2500 3A 0.0000 3.2500 3.2406 — 3.2094 3.2052 3.1755 3B 3.1820 3.1908 3.2094 3.2149 3.2500 3 1 ⁄ 4 –18 UNS 2A 0.0016 3.2484 3.2397 — 3.2123 3.2069 3.1823 2B 3.190 3.203 3.2139 3.2209 3.2500 3 3 ⁄ 8 –6 UN 2A 0.0029 3.3721 3.3539 — 3.2638 3.2543 3.1737 2B 3.195 3.225 3.2667 3.2791 3.3750 3A 0.0000 3.3750 3.3568 — 3.2667 3.2595 3.1766 3B 3.1950 3.2146 3.2667 3.2760 3.3750 3 3 ⁄ 8 –8 UN 2A 0.0026 3.3724 3.3574 — 3.2912 3.2824 3.2236 2B 3.240 3.265 3.2938 3.3052 3.3750 3A 0.0000 3.3750 3.3600 — 3.2938 3.2872 3.2262 3B 3.2400 3.2547 3.2938 3.3023 3.3750 3 3 ⁄ 8 –12 UN 2A 0.0019 3.3731 3.3617 — 3.3190 3.3126 3.2739 2B 3.285 3.303 3.3209 3.3293 3.3750 3A 0.0000 3.3750 3.3636 — 3.3209 3.3161 3.2758 3B 3.2850 3.2948 3.3209 3.3272 3.3750 3 3 ⁄ 8 –16 UN 2A 0.0017 3.3733 3.3639 — 3.3327 3.3269 3.2988 2B 3.307 3.321 3.3344 3.3419 3.3750 3A 0.0000 3.3750 3.3656 — 3.3344 3.3301 3.3005 3B 3.3070 3.3158 3.3344 3.3400 3.3750 3 1 ⁄ 2 –4 UNC 1A 0.0033 3.4967 3.4610 — 3.3343 3.3177 3.1990 1B 3.229 3.267 3.3376 3.3591 3.5000 2A 0.0033 3.4967 3.4729 3.4610 3.3343 3.3233 3.1990 2B 3.229 3.267 3.3376 3.3519 3.5000 3A 0.0000 3.5000 3.4762 — 3.3376 3.3293 3.2023 3B 3.2290 3.2594 3.3376 3.3484 3.5000 3 1 ⁄ 2 –6 UN 2A 0.0029 3.4971 3.4789 — 3.3888 3.3792 3.2987 2B 3.320 3.350 3.3917 3.4042 3.5000 3A 0.0000 3.5000 3.4818 — 3.3917 3.3845 3.3016 3B 3.3200 3.3396 3.3917 3.4011 3.5000 3 1 ⁄ 2 –8 UN 2A 0.0026 3.4974 3.4824 3.4749 3.4162 3.4074 3.3486 2B 3.365 3.390 3.4188 3.4303 3.5000 3A 0.0000 3.5000 3.4850 — 3.4188 3.4122 3.3512 3B 3.3650 3.3797 3.4188 3.4274 3.5000 3 1 ⁄ 2 –10 UNS 2A 0.0021 3.4979 3.4850 — 3.4329 3.4260 3.3789 2B 3.392 3.413 3.4350 3.4440 3.5000 3 1 ⁄ 2 –12 UN 2A 0.0019 3.4981 3.4867 — 3.4440 3.4376 3.3989 2B 3.410 3.428 3.4459 3.4543 3.5000 3A 0.0000 3.5000 3.4886 — 3.4459 3.4411 3.4008 3B 3.4100 3.4198 3.4459 3.4522 3.5000 Table 3. (Continued) Standard Series and Selected Combinations — Unified Screw Threads Nominal Size, Threads per Inch, and Series Designation a External b Internal b Class Allow- ance Major Diameter Pitch Diameter UNR Minor Dia., c Max (Ref.) Class Minor Diameter Pitch Diameter Major Diameter Max d Min Min e Max d Min Min Max Min Max Min Machinery's Handbook 27th Edition Copyright 2004, Industrial Press, Inc., New York, NY UNIFIED SCREW THREADS 1759 3 1 ⁄ 2 –14 UNS 2A 0.0018 3.4982 3.4879 — 3.4518 3.4457 3.4132 2B 3.423 3.438 3.4536 3.4615 3.5000 3 1 ⁄ 2 –16 UN 2A 0.0017 3.4983 3.4889 — 3.4577 3.4519 3.4238 2B 3.432 3.446 3.4594 3.4669 3.5000 3A 0.0000 3.5000 3.4906 — 3.4594 3.4551 3.4255 3B 3.4320 3.4408 3.4594 3.4650 3.5000 3 1 ⁄ 2 –18 UNS 2A 0.0017 3.4983 3.4896 — 3.4622 3.4567 3.4322 2B 3.440 3.453 3.4639 3.4711 3.5000 3 5 ⁄ 8 –6 UN 2A 0.0029 3.6221 3.6039 — 3.5138 3.5041 3.4237 2B 3.445 3.475 3.5167 3.5293 3.6250 3A 0.0000 3.6250 3.6068 — 3.5167 3.5094 3.4266 3B 3.4450 3.4646 3.5167 3.5262 3.6250 3 5 ⁄ 8 –8 UN 2A 0.0027 3.6223 3.6073 — 3.5411 3.5322 3.4735 2B 3.490 3.515 3.5438 3.5554 3.6250 3A 0.0000 3.6250 3.6100 — 3.5438 3.5371 3.4762 3B 3.4900 3.5047 3.5438 3.5525 3.6250 3 5 ⁄ 8 –12 UN 2A 0.0019 3.6231 3.6117 — 3.5690 3.5626 3.5239 2B 3.535 3.553 3.5709 3.5793 3.6250 3A 0.0000 3.6250 3.6136 — 3.5709 3.5661 3.5258 3B 3.5350 3.5448 3.5709 3.5772 3.6250 3 5 ⁄ 8 –16 UN 2A 0.0017 3.6233 3.6139 — 3.5827 3.5769 3.5488 2B 3.557 3.571 3.5844 3.5919 3.6250 3A 0.0000 3.6250 3.6156 — 3.5844 3.5801 3.5505 3B 3.5570 3.5658 3.5844 3.5900 3.6250 3 3 ⁄ 4 –4 UNC 1A 0.0034 3.7466 3.7109 — 3.5842 3.5674 3.4489 1B 3.479 3.517 3.5876 3.6094 3.7500 2A 0.0034 3.7466 3.7228 3.7109 3.5842 3.5730 3.4489 2B 3.479 3.517 3.5876 3.6021 3.7500 3A 0.0000 3.7500 3.7262 — 3.5876 3.5792 3.4523 3B 3.4790 3.5094 3.5876 3.5985 3.7500 3 3 ⁄ 4 –6 UN 2A 0.0029 3.7471 3.7289 — 3.6388 3.6290 3.5487 2B 3.570 3.600 3.6417 3.6544 3.7500 3A 0.0000 3.7500 3.7318 — 3.6417 3.6344 3.5516 3B 3.5700 3.5896 3.6417 3.6512 3.7500 3 3 ⁄ 4 –8 UN 2A 0.0027 3.7473 3.7323 3.7248 3.6661 3.6571 3.5985 2B 3.615 3.640 3.6688 3.6805 3.7500 3A 0.0000 3.7500 3.7350 — 3.6688 3.6621 3.6012 3B 3.6150 3.6297 3.6688 3.6776 3.7500 3 3 ⁄ 4 –10 UNS 2A 0.0021 3.7479 3.7350 — 3.6829 3.6760 3.6289 2B 3.642 3.663 3.6850 3.6940 3.7500 3 3 ⁄ 4 –12 UN 2A 0.0019 3.7481 3.7367 — 3.6940 3.6876 3.6489 2B 3.660 3.678 3.6959 3.7043 3.7500 3A 0.0000 3.7500 3.7386 — 3.6959 3.6911 3.6508 3B 3.6600 3.6698 3.6959 3.7022 3.7500 3 3 ⁄ 4 –14 UNS 2A 0.0018 3.7482 3.7379 — 3.7018 3.6957 3.6632 2B 3.673 3.688 3.7036 3.7115 3.7500 3 3 ⁄ 4 –16 UN 2A 0.0017 3.7483 3.7389 — 3.7077 3.7019 3.6738 2B 3.682 3.696 3.7094 3.7169 3.7500 3A 0.0000 3.7500 3.7406 — 3.7094 3.7051 3.6755 3B 3.6820 3.6908 3.7094 3.7150 3.7500 3 3 ⁄ 4 –18 UNS 2A 0.0017 3.7483 3.7396 — 3.7122 3.7067 3.6822 2B 3.690 3.703 3.7139 3.7211 3.7500 Table 3. (Continued) Standard Series and Selected Combinations — Unified Screw Threads Nominal Size, Threads per Inch, and Series Designation a External b Internal b Class Allow- ance Major Diameter Pitch Diameter UNR Minor Dia., c Max (Ref.) Class Minor Diameter Pitch Diameter Major Diameter Max d Min Min e Max d Min Min Max Min Max Min Machinery's Handbook 27th Edition Copyright 2004, Industrial Press, Inc., New York, NY UNIFIED SCREW THREADS1760 3 7 ⁄ 8 –6 UN 2A 0.0030 3.8720 3.8538 — 3.7637 3.7538 3.6736 2B 3.695 3.725 3.7667 3.7795 3.8750 3A 0.0000 3.8750 3.8568 — 3.7667 3.7593 3.6766 3B 3.6950 3.7146 3.7667 3.7763 3.8750 3 7 ⁄ 8 –8 UN 2A 0.0027 3.8723 3.8573 — 3.7911 3.7820 3.7235 2B 3.740 3.765 3.7938 3.8056 3.8750 3A 0.0000 3.8750 3.8600 — 3.7938 3.7870 3.7262 3B 3.7400 3.7547 3.7938 3.8026 3.8750 3 7 ⁄ 8 –12 UN 2A 0.0020 3.8730 3.8616 — 3.8189 3.8124 3.7738 2B 3.785 3.803 3.8209 3.8294 3.8750 3A 0.0000 3.8750 3.8636 — 3.8209 3.8160 3.7758 3B 3.7850 3.7948 3.8209 3.8273 3.8750 3 7 ⁄ 8 –16 UN 2A 0.0018 3.8732 3.8638 — 3.8326 3.8267 3.7987 2B 3.807 3.821 3.8344 3.8420 3.8750 3A 0.0000 3.8750 3.8656 — 3.8344 3.8300 3.8005 3B 3.8070 3.8158 3.8344 3.8401 3.8750 4–4 UNC 1A 0.0034 3.9966 3.9609 — 3.8342 3.8172 3.6989 1B 3.729 3.767 3.8376 3.8597 4.0000 2A 0.0034 3.9966 3.9728 3.9609 3.8342 3.8229 3.6989 2B 3.729 3.767 3.8376 3.8523 4.0000 3A 0.0000 4.0000 3.9762 — 3.8376 3.8291 3.7023 3B 3.7290 3.7594 3.8376 3.8487 4.0000 4–6 UN 2A 0.0030 3.9970 3.9788 — 3.8887 3.8788 3.7986 2B 3.820 3.850 3.8917 3.9046 4.0000 3A 0.0000 4.0000 3.9818 — 3.8917 3.8843 3.8016 3B 3.8200 3.8396 3.8917 3.9014 4.0000 4–8 UN 2A 0.0027 3.9973 3.9823 3.9748 3.9161 3.9070 3.8485 2B 3.865 3.890 3.9188 3.9307 4.0000 3A 0.0000 4.0000 3.9850 — 3.9188 3.9120 3.8512 3B 3.8650 3.8797 3.9188 3.9277 4.0000 4–10 UNS 2A 0.0021 3.9979 3.9850 — 3.9329 3.9259 3.8768 2B 3.892 3.913 3.9350 3.9441 4.0000 4–12 UN 2A 0.0020 3.9980 3.9866 — 3.9439 3.9374 3.8988 2B 3.910 3.928 3.9459 3.9544 4.0000 3A 0.0000 4.0000 3.9886 — 3.9459 3.9410 3.9008 3B 3.9100 3.9198 3.9459 3.9523 4.0000 4–14 UNS 2A 0.0018 3.9982 3.9879 — 3.9518 3.9456 3.9132 2B 3.923 3.938 3.9536 3.9616 4.0000 4–16 UN 2A 0.0018 3.9982 3.9888 — 3.9576 3.9517 3.9237 2B 3.932 3.946 3.9594 3.9670 4.0000 3A 0.0000 4.0000 3.9906 — 3.9594 3.9550 3.9255 3B 3.9320 3.9408 3.9594 3.9651 4.0000 4 1 ⁄ 4 –10 UNS 2A 0.0021 4.2479 4.2350 — 4.1829 4.1759 4.1289 2B 4.142 4.163 4.1850 4.1941 4.2500 4 1 ⁄ 4 –14 UNS 2A 0.0018 4.2482 4.2379 — 4.2018 4.1956 4.1632 2B 4.173 4.188 4.2036 4.2116 4.2500 4 1 ⁄ 4 –12 UN 2A 0.0020 4.2480 4.2366 — 4.1939 4.1874 4.1488 2B 4.160 4.178 4.1959 4.2044 4.2500 3A 0.0000 4.2500 4.2386 — 4.1959 4.1910 4.1508 3B 4.1600 4.1698 4.1959 4.2023 4.2500 4 1 ⁄ 4 –16 UN 2A 0.0018 4.2482 4.2388 — 4.2076 4.2017 4.1737 2B 4.182 4.196 4.2094 4.2170 4.2500 3A 0.0000 4.2500 4.2406 — 4.2094 4.2050 4.1755 3B 4.1820 4.1900 4.2094 4.2151 4.2500 4 1 ⁄ 2 –10 UNS 2A 0.0021 4.4979 4.4850 — 4.4329 4.4259 4.3789 2B 4.392 4.413 4.4350 4.4441 4.5000 4 1 ⁄ 2 –14 UNS 2A 0.0018 4.4982 4.4879 — 4.4518 4.4456 4.4132 2B 4.423 4.438 4.4536 4.4616 4.5000 Table 3. (Continued) Standard Series and Selected Combinations — Unified Screw Threads Nominal Size, Threads per Inch, and Series Designation a External b Internal b Class Allow- ance Major Diameter Pitch Diameter UNR Minor Dia., c Max (Ref.) Class Minor Diameter Pitch Diameter Major Diameter Max d Min Min e Max d Min Min Max Min Max Min Machinery's Handbook 27th Edition Copyright 2004, Industrial Press, Inc., New York, NY UNIFIED SCREW THREADS 1761 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 4 3 ⁄ 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 4 3 ⁄ 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 5 1 ⁄ 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 5 1 ⁄ 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 5 1 ⁄ 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 5 1 ⁄ 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 5 1 ⁄ 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 5 1 ⁄ 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 5 1 ⁄ 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 5 1 ⁄ 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 Table 3. (Continued) Standard Series and Selected Combinations — Unified Screw Threads Nominal Size, Threads per Inch, and Series Designation a External b Internal b Class Allow- ance Major Diameter Pitch Diameter UNR Minor Dia., c Max (Ref.) Class Minor Diameter Pitch Diameter Major Diameter Max d Min Min e Max d Min Min Max Min Max Min Machinery's Handbook 27th Edition Copyright 2004, Industrial Press, Inc., New York, NY UNIFIED SCREW THREADS1762 All dimensions in inches. Use UNS threads only if Standard Series do not meet requirements (see pages 1733, 1765, and 1776). For additional sizes above 4 inches see ASME/ANSI B1.1- 1989 (R2001). 5 3 ⁄ 4 –10 UNS 2A 0.0022 5.7478 5.7349 — 5.6828 5.6754 5.6288 2B 5.642 5.663 5.6850 5.6946 5.7500 5 3 ⁄ 4 –14 UNS 2A 0.0020 5.7480 5.7377 — 5.7016 5.6951 5.6630 2B 5.673 5.688 5.7036 5.7121 5.7500 5 3 ⁄ 4 –12 UN 2A 0.0021 5.7479 5.7365 — 5.6938 5.6869 5.6487 2B 5.660 5.678 5.6959 5.7049 5.7500 3A 0.0000 5.7500 5.7386 — 5.6959 5.6907 5.6508 3B 5.6600 5.6698 5.6959 5.7026 5.7500 5 3 ⁄ 4 –16 UN 2A 0.0019 5.7481 5.7387 — 5.7075 5.7013 5.6736 2B 5.682 5.696 5.7094 5.7175 5.7500 3A 0.0000 5.7500 5.7406 — 5.7094 5.7047 5.6755 3B 5.6820 5.6908 5.7094 5.7155 5.7500 6–10 UNS 2A 0.0022 5.9978 5.9849 — 5.9328 5.9254 5.8788 2B 5.892 5.913 5.9350 5.9446 6.0000 6–14 UNS 2A 0.0020 5.9980 5.9877 — 5.9516 5.9451 5.9130 2B 5.923 5.938 5.9536 5.9621 6.0000 6–12 UN 2A 0.0021 5.9979 5.9865 — 5.9438 5.9369 5.8987 2B 5.910 5.928 5.9459 5.9549 6.0000 3A 0.0000 6.0000 5.9886 — 5.9459 5.9407 5.9008 3B 5.9100 5.9198 5.9459 5.9526 6.0000 6–16 UN 2A 0.0019 5.9981 5.9887 — 5.9575 5.9513 5.9236 2B 5.932 5.946 5.9594 5.9675 6.0000 3A 0.0000 6.0000 5.9906 — 5.9594 5.9547 5.9255 3B 5.9320 5.9408 5.9594 5.9655 6.0000 a Use UNR designation instead of UN wherever UNR thread form is desired for external use. b Regarding combinations of thread classes, see text on page 1773. c UN series external thread maximum minor diameter is basic for Class 3A and basic minus allowance for Classes 1A and 2A. d For Class 2A threads having an additive finish the maximum is increased, by the allowance, to the basic size, the value being the same as for Class 3A. e For unfinished hot-rolled material not including standard fasteners with rolled threads. f Formerly NF, tolerances and allowances are based on one diameter length of engagement. Table 3. (Continued) Standard Series and Selected Combinations — Unified Screw Threads Nominal Size, Threads per Inch, and Series Designation a External b Internal b Class Allow- ance Major Diameter Pitch Diameter UNR Minor Dia., c Max (Ref.) Class Minor Diameter Pitch Diameter Major Diameter Max d Min Min e Max d Min Min Max Min Max Min Machinery's Handbook 27th Edition Copyright 2004, Industrial Press, Inc., New York, NY UNIFIED SCREW THREADS 1763 Coarse-Thread Series: This series, UNC/UNRC, is the one most commonly used in the bulk production of bolts, screws, nuts and other general engineering applications. It is also used for threading into lower tensile strength materials such as cast iron, mild steel and softer materials (bronze, brass, aluminum, magnesium and plastics) to obtain the optimum resistance to stripping of the internal thread. It is applicable for rapid assembly or disas- sembly, or if corrosion or slight damage is possible. Table 4a. Coarse-Thread Series, UNC and UNRC — Basic Dimensions Fine-Thread Series: This series, UNF/UNRF, is suitable for the production of bolts, screws, and nuts and for other applications where the Coarse series is not applicable. Exter- nal threads of this series have greater tensile stress area than comparable sizes of the Coarse series. The Fine series is suitable when the resistance to stripping of both external Sizes No. or Inches Basic Major Dia., D Thds. per Inch, n Basic Pitch Dia., a D 2 a British: Effective Diameter. Minor Diameter Lead Angle λ at Basic P. D. Area of Minor Dia. at D-2h b Tensile Stress Area b b See formula, pages 1502 and 1510. Ext. Thds., c d 3 (Ref.) c Design form for UNR threads. (See figure on page 1733.) Int. Thds., d D 1 d Basic minor diameter. Inches Inches Inches Inches Deg. Min Sq. In. Sq. In. 1 (0.073) e e Secondary sizes. 0.0730 64 0.0629 0.0544 0.0561 4 31 0.00218 0.00263 2 (0.086) 0.0860 56 0.0744 0.0648 0.0667 4 22 0.00310 0.00370 3 (0.099) e 0.0990 48 0.0855 0.0741 0.0764 4 26 0.00406 0.00487 4 (0.112) 0.1120 40 0.0958 0.0822 0.0849 4 45 0.00496 0.00604 5 (0.125) 0.1250 40 0.1088 0.0952 0.0979 4 11 0.00672 0.00796 6 (0.138) 0.1380 32 0.1177 0.1008 0.1042 4 50 0.00745 0.00909 8 (0.164) 0.1640 32 0.1437 0.1268 0.1302 3 58 0.01196 0.0140 10 (0.190) 0.1900 24 0.1629 0.1404 0.1449 4 39 0.01450 0.0175 12 (0.216) e 0.2160 24 0.1889 0.1664 0.1709 4 1 0.0206 0.0242 1 ⁄ 4 0.2500 20 0.2175 0.1905 0.1959 4 11 0.0269 0.0318 5 ⁄ 16 0.3125 18 0.2764 0.2464 0.2524 3 40 0.0454 0.0524 3 ⁄ 8 0.3750 16 0.3344 0.3005 0.3073 3 24 0.0678 0.0775 7 ⁄ 16 0.4375 14 0.3911 0.3525 0.3602 3 20 0.0933 0.1063 1 ⁄ 2 0.5000 13 0.4500 0.4084 0.4167 3 7 0.1257 0.1419 9 ⁄ 16 0.5625 12 0.5084 0.4633 0.4723 2 59 0.162 0.182 5 ⁄ 8 0.6250 11 0.5660 0.5168 0.5266 2 56 0.202 0.226 3 ⁄ 4 0.7500 10 0.6850 0.6309 0.6417 2 40 0.302 0.334 7 ⁄ 8 0.8750 9 0.8028 0.7427 0.7547 2 31 0.419 0.462 1 1.0000 8 0.9188 0.8512 0.8647 2 29 0.551 0.606 1 1 ⁄ 8 1.1250 7 1.0322 0.9549 0.9704 2 31 0.693 0.763 1 1 ⁄ 4 1.2500 7 1.1572 1.0799 1.0954 2 15 0.890 0.969 1 3 ⁄ 8 1.3750 6 1.2667 1.1766 1.1946 2 24 1.054 1.155 1 1 ⁄ 2 1.5000 6 1.3917 1.3016 1.3196 2 11 1.294 1.405 1 3 ⁄ 4 1.7500 5 1.6201 1.5119 1.5335 2 15 1.74 1.90 22.0000 4 1 ⁄ 2 1.8557 1.7353 1.7594 2 11 2.30 2.50 2 1 ⁄ 4 2.2500 4 1 ⁄ 2 2.1057 1.9853 2.0094 1 55 3.02 3.25 2 1 ⁄ 2 2.5000 4 2.3376 2.2023 2.2294 1 57 3.72 4.00 2 3 ⁄ 4 2.7500 4 2.5876 2.4523 2.4794 1 46 4.62 4.93 3 3.0000 4 2.8376 2.7023 2.7294 1 36 5.62 5.97 3 1 ⁄ 4 3.2500 4 3.0876 2.9523 2.9794 1 29 6.72 7.10 3 1 ⁄ 4 3.500 4 3.3376 3.2023 3.2294 1 22 7.92 8.33 3 3 ⁄ 4 3.7500 4 3.5876 3.4523 3.4794 1 16 9.21 9.66 4 4.0000 4 3.8376 3.7023 3.7294 1 11 10.61 11.08 Machinery's Handbook 27th Edition Copyright 2004, Industrial Press, Inc., New York, NY [...]... 70.6 63 70.6 63 73. 994 73. 994 76.0 23 76.0 23 78.6 63 78.6 63 78.994 78.994 83. 6 63 83. 6 63 86.0 23 86.0 23 88.6 63 88.6 63 93. 6 63 93. 6 63 96.0 23 96.0 23 98.6 63 98.6 63 1 03. 6 63 1 03. 6 63 108.6 63 108.6 63 118.6 63 118.6 63 128.6 63 138 .6 63 138 .6 63 138 .6 63 148.6 63 148.6 63 158.0 03 158.0 03 168.0 03 168.0 03 178.0 03 178.0 03 188.0 03 188.0 03 198.0 03 198.0 03 Min 70.4 83 70.551 73. 834 73. 894 75.7 43 75.8 43 78.4 83 78.551 78. 834 78.894 83. 4 83. .. 28.6 63 28.6 63 28.994 28.994 31 .6 63 31.6 63 33. 994 33 .34 2 33 .34 2 34 .6 63 34.6 63 37.6 63 37.6 63 38.994 38 .994 39 .014 39 .014 40.6 63 40.6 63 43. 994 43. 994 44.681 44.681 46.6 63 46.6 63 48.994 48.994 53. 994 53. 994 52 .35 3 52 .35 3 54.6 63 54.6 63 58.994 58.994 60.0 23 60.0 23 62.6 63 62.6 63 63. 994 63. 994 68.994 68.994 68.0 23 68.0 23 Min 21.8 03 21.878 22.4 93 22.557 23. 844 23. 899 24.8 03 25.4 93 25.557 27.462 27.542 28.4 93 28.557... 39 .797 43. 344 43. 344 42.516 42.516 45.797 45.797 48 .34 4 48 .34 4 53. 344 53. 344 49.971 49.971 53. 797 53. 797 58 .34 4 58 .34 4 57.425 57.425 61.797 61.797 63. 344 63. 344 68 .34 4 68 .34 4 65.425 65.425 Min 19.955 20. 030 21.261 21 .32 5 22.920 22.975 22.955 24.261 24 .32 5 25 .30 6 25 .38 6 27.261 27 .32 5 27.920 27.975 30 .261 30 .32 5 33 .920 30 .654 30 . 738 33 .261 33 .32 5 36 .261 36 .32 5 37 .920 37 .975 36 .006 36 .092 39 .261 39 .32 5 42.920... 32 .682 32 .682 34 . 732 35 .465 35 .465 35 .682 35 .682 38 .682 38 .682 39 . 732 39 . 732 41. 437 41. 437 41.682 41.682 44. 732 44. 732 47 .39 9 47 .39 9 47.682 47.682 49. 732 49. 732 54. 732 54. 732 55 .36 5 55 .36 5 55.682 55.682 59. 732 59. 732 63. 320 63. 320 63. 682 63. 682 64. 732 64. 732 69. 732 69. 732 71 .32 0 71 .32 0 MinorDiam.,d1b Pitch Diam.b d2 Major Diam.b d Max 22.0 03 22.0 03 22.6 63 22.6 63 23. 994 23. 994 25.0 03 25.6 63 25.6 63 27.674... 4g6g Allow esa 0.048 0.048 0. 038 0. 038 0. 032 0. 032 0.048 0. 038 0. 038 0.0 53 0.0 53 0. 038 0. 038 0. 032 0. 032 0. 038 0. 038 0. 032 0.060 0.060 0. 038 0. 038 0. 038 0. 038 0. 032 0. 032 0.0 63 0.0 63 0. 038 0. 038 0. 032 0. 032 0.071 0.071 0. 038 0. 038 0. 032 0. 032 0. 032 0. 032 0.075 0.075 0. 038 0. 038 0. 032 0. 032 0.080 0.080 0. 038 0. 038 0. 032 0. 032 0. 032 0. 032 0.080 0.080 Max 23. 952 23. 952 23. 962 23. 962 24.968 24.968 26.952... 2.68 23 2.80 73 2. 932 3 3. 05 73 3.18 23 3 .30 73 3. 432 3 3. 55 73 3.68 23 3.80 73 3. 932 3 4.05 73 4.18 23 4 .30 73 4. 432 3 4.55 73 4.68 23 4.80 73 4. 932 3 5.05 73 5.18 23 5 .30 73 Ext Thds.,c d3 (Ref.) Int Thds.,d D1 Lead Angle λ at Basic P.D Deg Min 3 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 24 52 29 11 57 46 36 29 22 16 11 7 3 0 57 54 51 49 47 45 43 42 40 39 37 36 ... 39 . 835 43. 376 42.587 45. 835 48 .37 6 53. 376 50.046 53. 835 58 .37 6 57.505 61. 835 63. 376 68 .37 6 65.505 69. 835 73. 376 73. 505 77. 835 78 .37 6 82. 835 83. 505 87. 835 92. 835 93. 505 97. 835 102. 835 107. 835 117. 835 127. 835 137 . 835 147. 835 156.752 166.752 176.752 186.752 196.752 Max 19.744 20.676 21.252 22.210 23. 676 24.252 25.210 26.771 28.210 28.676 31 .210 33 .676 32 .270 34 .210 37 .210 38 .676 37 .799 40.210 43. 676 43. 297... 28.4 93 28.557 28.844 28.899 31 .4 93 31.557 33 .844 33 .118 33 .202 34 .4 93 34.557 37 .4 93 37.557 38 .844 38 .899 38 .778 38 .864 40.4 93 40.557 43. 844 43. 899 44. 431 44.521 46.4 83 46.551 48. 834 48.894 53. 834 53. 894 52.088 52.1 83 54.4 83 54.551 58. 834 58.894 59.7 43 59.8 43 62.4 83 62.551 63. 834 63. 894 68. 834 68.894 67.7 43 67.8 43 Tol 0.200 0.125 0.170 0.106 0.150 0.095 0.200 0.170 0.106 0.212 0. 132 0.170 0.106 0.150 0.095... 2.1755 2 .30 05 2.4255 2.5505 2.6755 2.8005 2.9255 3. 0505 3. 1755 3. 3005 3. 4255 3. 5505 3. 6755 3. 8005 3. 9255 4.0505 4.1755 4 .30 05 4.4255 4.5505 4.6755 4.8005 4.9255 5.0505 5.1755 5 .30 05 0 .30 73 0 .36 98 0. 432 3 0.4948 0.55 73 0.6198 0.68 23 0.7448 0.80 73 0.8698 0. 932 3 0.9948 1.05 73 1.1198 1.18 23 1.2448 1 .30 73 1 .36 98 1. 432 3 1.4948 1.55 73 1.6198 1.68 23 1.7448 1.80 73 1.8698 1. 932 3 2.05 73 2.18 23 2 .30 73 2. 432 3 2.55 73 2.68 23. .. 5 .37 50 5.5000 5.6250 5.7500 5.8750 6.0000 Secondary Inches 21⁄2e Basic Pitch Dia.,a D2 Basic Major Dia., D Inches 2 .33 76 2.4626 2.5876 2.7126 2. 837 6 2.9626 3. 0876 3. 2126 3. 337 6 3. 4626 3. 5876 3. 7126 3. 837 6 3. 9626 4.0876 4.2126 4 .33 76 4.4626 4.5876 4.7126 4. 837 6 4.9626 5.0876 5.2126 5 .33 76 5.4626 5.5876 5.7126 5. 837 6 2.20 23 2 .32 73 2.45 23 2.57 73 2.70 23 2.82 73 2.95 23 3.07 73 3.20 23 3 .32 73 3.45 23 3.57 73 3.7023 . 3. 307 3. 321 3. 334 4 3. 3419 3. 3750 3A 0.0000 3. 3750 3. 3656 — 3. 334 4 3. 330 1 3. 3005 3B 3. 3070 3. 3158 3. 334 4 3. 3400 3. 3750 3 1 ⁄ 2 –4 UNC 1A 0.0 033 3. 4967 3. 4610 — 3. 334 3 3. 3177 3. 1990 1B 3. 229 3. 267. 3. 2 739 2B 3. 285 3. 3 03 3 .32 09 3. 32 93 3 .37 50 3A 0.0000 3. 3750 3. 3 636 — 3. 3209 3. 3161 3. 2758 3B 3. 2850 3. 2948 3. 3209 3. 3272 3. 3750 3 3 ⁄ 8 –16 UN 2A 0.0017 3. 3 733 3. 3 639 — 3. 332 7 3. 3269 3. 2988 2B 3. 307. 3. 267 3. 337 6 3. 3591 3. 5000 2A 0.0 033 3. 4967 3. 4729 3. 4610 3. 334 3 3. 3 233 3. 1990 2B 3. 229 3. 267 3. 337 6 3. 3519 3. 5000 3A 0.0000 3. 5000 3. 4762 — 3. 337 6 3. 32 93 3.20 23 3B 3. 2290 3. 2594 3. 337 6 3. 3484 3. 5000 3 1 ⁄ 2 –6