This table contains stress area, proof load, clamp load and assembly torques (dry and lubricated) for threaded fasteners ranging in thread size from #4 to 4-1/2 inch nominal Unified thread size. Data is provided for grade 2, grade 5, grade 8 and grade 9 fasteners.
NOTES: 1) Clamp load = 75% * Proof * stress area. 2) Torque is R * D * T where R = .200 (dry) or .150 (lubricated), D = Nominal diameter (inch) and T = Desired clamp load (lbs). Lubricated includes lubricants, lubrizing plating and hardened washers.
Nominal Clamp Assembly Torque
size or Stress Proof Load -----------------------------------
basic major Area Grade Load (1) Dry Lubricated Dry Lubricated
diameter ------- ----- ----- ------- ------ ---------- ------ ----------
of thread in^2 ksi lbs in*lb in*lb ft*lb ft*lb
---------------- ------- ----- ----- ------- ------ ---------- ------ ----------
# 4-40 0.1120 .0060 2 55 248 5 4
# 4-40 0.1120 .0060 5 85 384 18 6
# 4-40 0.1120 .0060 8 120 542 12 9
# 4-48 0.1120 .0066 2 55 272 6 4
# 4-48 0.1120 .0060 5 85 421 19 17
# 4-48 0.1120 .0060 8 120 594 13 9
# 6-32 0.1380 .0091 2 55 374 10 7
# 6-32 0.1380 .0091 5 85 579 15 11
# 6-32 0.1380 .0091 8 120 817 22 8
# 6-36 0.1380 .0101 2 55 418 11 8
# 6-36 0.1380 .0101 5 85 646 17 13
# 6-36 0.1380 .0101 8 120 912 25 18
# 8-32 0.1640 .0140 2 55 577 18 14
# 8-32 0.1640 .0140 5 85 893 29 21
# 8-32 0.1640 .0140 8 120 1260 41 31
# 8-36 0.1640 .0147 2 55 607 19 14
# 8-36 0.1640 .0147 5 85 938 30 23
# 8-36 0.1640 .0147 8 120 1325 43 32
#10-24 0.1900 .0175 2 55 723 27 20
#10-24 0.1900 .0175 5 85 1117 42 31
#10-24 0.1900 .0175 8 120 1577 59 44
#10-32 0.1900 .0200 2 55 824 31 23
#10-32 0.1900 .0200 5 85 1274 48 36
#10-32 0.1900 .0200 8 120 1799 68 51
1/4-20 0.2500 .0318 2 55 723 65 49
1/4-20 0.2500 .0318 5 85 1117 101 76
1/4-20 0.2500 .0318 8 120 1577 143 107
1/4-20 0.2500 .0318 9 145 3460 173 129
1/4-28 0.2500 .0364 2 55 824 75 56
1/4-28 0.2500 .0364 5 85 1274 115 86
1/4-28 0.2500 .0364 8 120 1799 163 122
1/4-28 0.2500 .0364 9 145 3955 197 148
5/16-18 0.3125 .0524 2 55 2162 11 8
5/16-18 0.3125 .0524 5 85 3342 17 13
5/16-18 0.3125 .0524 8 120 4718 24 18
5/16-18 0.3125 .0524 9 145 5701 29 22
5/16-24 0.3125 .0581 2 55 2395 11 8
5/16-24 0.3125 .0581 5 85 3701 19 14
5/16-24 0.3125 .0581 8 120 5225 27 20
5/16-24 0.3125 .0581 9 145 6314 32 24
3/8-18 0.3750 .0775 2 55 3196 19 14
3/8-18 0.3750 .0775 5 85 4939 30 23
3/8-18 0.3750 .0775 8 120 6974 43 32
3/8-18 0.3750 .0775 9 145 8427 52 39
3/8-24 0.3750 .0878 2 55 3622 22 16
3/8-24 0.3750 .0878 5 85 5599 34 26
3/8-24 0.3750 .0878 8 120 7904 49 37
3/8-24 0.3750 .0878 9 145 9551 59 44
7/16-14 0.4375 .1063 2 55 4385 31 23
7/16-14 0.4375 .1063 5 85 6777 49 37
7/16-14 0.4375 .1063 8 120 9567 69 52
7/16-14 0.4375 .1063 9 145 11561 84 63
7/16-20 0.4375 .1187 2 55 4897 35 26
7/16-20 0.4375 .1187 5 85 7568 55 41
7/16-20 0.4375 .1187 8 120 10684 77 58
7/16-20 0.4375 .1187 9 145 12910 94 70
1/2-13 0.5000 .1419 2 55 5853 48 36
1/2-13 0.5000 .1419 5 85 9046 75 56
1/2-13 0.5000 .1419 8 120 12770 106 79
1/2-13 0.5000 .1419 9 145 15431 128 96
1/2-20 0.5000 .1600 2 55 6598 54 41
1/2-20 0.5000 .1600 5 85 10197 84 63
1/2-20 0.5000 .1600 8 120 14395 153 115
1/2-20 0.5000 .1600 9 145 17394 144 108
9/16-12 0.5625 .1819 2 55 7505 70 52
9/16-12 0.5625 .1819 5 85 11598 108 81
9/16-12 0.5625 .1819 8 120 16375 106 79
9/16-12 0.5625 .1819 9 145 19786 185 139
9/16-18 0.5625 .2030 2 55 8372 78 58
9/16-18 0.5625 .2030 5 85 12940 121 90
9/16-18 0.5625 .2030 8 120 18268 171 128
9/16-18 0.5625 .2030 9 145 22074 206 155
5/8-11 0.6250 .2260 2 55 9322 97 72
5/8-11 0.6250 .2260 5 85 14407 150 112
5/8-11 0.6250 .2260 8 120 20340 211 158
5/8-11 0.6250 .2260 9 145 24577 256 192
5/8-18 0.6250 .2560 2 55 10558 109 82
5/8-18 0.6250 .2560 5 85 16317 169 127
5/8-18 0.6250 .2560 8 120 23036 239 179
5/8-18 0.6250 .2560 9 145 27835 289 217
3/4-10 0.7500 .3345 2 55 13796 97 72
3/4-10 0.7500 .3345 5 85 21321 266 199
3/4-10 0.7500 .3345 8 120 30101 376 282
3/4-10 0.7500 .3345 9 145 36372 454 340
3/4-16 0.7500 .3730 2 55 15384 192 144
3/4-16 0.7500 .3730 5 85 23776 297 222
3/4-16 0.7500 .3730 8 120 33566 419 314
3/4-16 0.7500 .3730 9 145 40559 506 380
7/8-9 0.8750 .4617 2 33 13796 97 72
7/8-9 0.8750 .4617 5 85 21321 266 199
7/8-9 0.8750 .4617 8 120 30101 376 282
7/8-9 0.8750 .4617 9 145 36372 454 340
7/8-14 0.8750 .5095 2 33 15384 192 144
7/8-14 0.8750 .5095 5 85 23776 297 222
7/8-14 0.8750 .5095 8 120 33566 419 314
7/8-14 0.8750 .5095 9 145 40559 506 380
1-8 1.0000 .6057 2 33 14992 249 187
1-8 1.0000 .6057 5 85 38616 643 482
1-8 1.0000 .6057 8 120 54517 908 681
1-8 1.0000 .6057 9 145 65874 1097 823
1-12 1.0000 .6630 2 33 16410 273 205
1-12 1.0000 .6630 5 85 42268 704 528
1-12 1.0000 .6630 8 120 59673 994 745
1-12 1.0000 .6630 9 145 72105 1201 901
1 1/8-7 1.1250 .7633 2 33 18891 354 265
1 1/8-7 1.1250 .7633 5 74 42361 794 595
1 1/8-7 1.1250 .7633 8 120 68694 1288 966
1 1/8-7 1.1250 .7633 9 145 83066 1556 1167
1 1/8-12 1.1250 .8557 2 33 21179 397 297
1 1/8-12 1.1250 .8557 5 74 47492 890 667
1 1/8-12 1.1250 .8557 8 120 77014 1444 1083
1 1/8-12 1.1250 .8557 9 145 93059 1477 1308
1 1/4-7 1.2500 .9691 2 33 23985 499 374
1 1/4-7 1.2500 .9691 5 74 53785 1120 840
1 1/4-7 1.2500 .9691 8 120 87220 1817 1362
1 1/4-7 1.2500 .9691 9 145 105391 2195 1646
1 1/4-12 1.2500 1.0729 2 33 26555 553 414
1 1/4-12 1.2500 1.0729 5 74 59548 1240 930
1 1/4-12 1.2500 1.0729 8 120 96565 2011 1508
1 1/4-12 1.2500 1.0729 9 145 116682 2430 1823
1 3/8-6 1.3750 1.1549 2 33 28583 655 491
1 3/8-6 1.3750 1.1549 5 74 64096 1468 1101
1 3/8-6 1.3750 1.1549 8 120 103939 2381 1786
1 3/8-6 1.3750 1.1549 9 145 125593 2878 2158
1 3/8-12 1.3750 1.3147 2 33 32539 745 559
1 3/8-12 1.3750 1.3147 5 74 72966 1672 1254
1 3/8-12 1.3750 1.3147 8 120 118324 2711 2033
1 3/8-12 1.3750 1.3147 9 145 142974 3276 2457
1 1/2-6 1.5000 1.4053 2 33 34780 869 652
1 1/2-6 1.5000 1.4053 5 74 77891 1949 1462
1 1/2-6 1.5000 1.4053 8 120 126472 3161 2371
1 1/2-6 1.5000 1.4053 9 145 152821 3820 2865
1 1/2-12 1.5000 1.5810 2 33 39130 978 733
1 1/2-12 1.5000 1.5810 5 74 87746 2193 1645
1 1/2-12 1.5000 1.5810 8 120 142292 3557 2667
1 1/2-12 1.5000 1.5810 9 145 171936 4298 3223
1 3/4-5 1.7500 1.8995 2 33 47011 1371 1028
1 3/4-5 1.7500 1.8995 5 74 105420 3074 2306
1 3/4-5 1.7500 1.8995 8 120 170951 4986 3739
2-4.5 2.0000 2.4982 2 33 61831 2061 1545
2-4.5 2.0000 2.4982 5 74 138651 4621 3466
2-4.5 2.0000 2.4982 8 120 224840 7497 5621
2 1/4-4.5 2.2500 3.2477 2 33 80380 3014 2260
2 1/4-4.5 2.2500 3.2477 5 74 180246 6759 5069
2 1/4-4.5 2.2500 3.2477 8 120 292292 10960 8220
2 1/2-4 2.5000 3.9988 2 33 98971 4213 3092
2 1/2-4 2.5000 3.9988 5 74 221935 9247 6935
2 1/2-4 2.5000 3.9988 8 120 359894 14995 11246
2 3/4-4 2.7500 4.9340 2 33 122166 5597 4197
2 3/4-4 2.7500 4.9340 5 74 273837 12550 9413
2 3/4-4 2.7500 4.9340 8 120 444061 20352 15264
3-4 3.0000 5.9674 2 33 147692 7384 5538
3-4 3.0000 5.9674 5 74 331189 16559 12419
3-4 3.0000 5.9674 8 120 537063 26853 20139
3 1/4-4 3.2500 7.0989 2 33 175698 9516 7137
3 1/4-4 3.2500 7.0989 5 74 393989 21341 16005
3 1/4-4 3.2500 7.0989 8 120 638901 34607 25955
3 1/2-4 3.5000 8.3286 2 33 206133 12024 9018
3 1/2-4 3.5000 8.3286 5 74 462238 26963 20222
3 1/2-4 3.5000 8.3286 8 120 749575 43725 32793
3 3/4-4 3.7500 9.6565 2 33 238998 14937 11203
3 3/4-4 3.7500 9.6565 5 74 535935 33495 25121
3 3/4-4 3.7500 9.6565 8 120 869085 54317 40738
4-4 4.0000 11.0826 2 33 274293 18286 13714
4-4 4.0000 11.0826 5 74 615082 41005 30754
4-4 4.0000 11.0826 8 120 997430 66495 49871
4 1/4-4 4.2500 12.6068 2 33 312018 22101 16575
4 1/4-4 4.2500 12.6068 5 74 699677 49560 37170
4 1/4-4 4.2500 12.6068 8 120 1134611 80368 60276
4 1/2-4 4.5000 14.2292 2 33 352172 26212 19809
4 1/2-4 4.5000 14.2292 5 74 789720 59229 44421
4 1/2-4 4.5000 14.2292 8 120 1280628 96047 72035
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