Bolt Torque Chart

Suggested Starting Values

The below estimated torque calculations are only offered as a guide. Use of its content by anyone is the sole responsibility of that person and they assume all risk. Due to many variables that affect the torque-tension relationship like human error, surface texture, and lubrication the only way to determine the correct torque is through experimentation under actual joint and assembly conditions.

ASTM A307

Bolt Size TPI Proof Load (lbs)1 Clamp Load (lbs)2
Tightening Torque (ft lbs)
Galv+Waxed Galv Plain
14 20 1,145 859 2 4 4
516 18 1,886 1,415 4 9 7
38 16 2,790 2,093 7 16 13
716 14 3,827 2,870 10 26 21
12 13 5,108 3,831 16 40 32
916 12 6,552 4,914 23 58 46
58 11 8,136 6,102 32 79 64
34 10 12,024 9,018 56 141 113
78 9 15,200 11,400 83 208 166
1 8 20,000 15,000 125 313 250
118 7 25,200 18,900 177 443 354
114 7 32,000 24,000 250 625 500
138 6 38,100 28,575 327 819 655
112 6 46,400 34,800 435 1,088 870
134 5 68,400 51,300 748 1,870 1,496
2 412 90,000 67,500 1,125 2,813 2,250
214 412 117,000 87,750 1,645 4,113 3,291
212 4 144,000 108,000 2,250 5,625 4,500
234 4 177,480 133,110 3,050 7,626 6,101
3 4 214,920 161,190 4,030 10,074 8,060
314 4 255,600 191,700 5,192 12,980 10,384
312 4 299,880 224,910 6,560 16,400 13,120
334 4 347,760 260,820 8,151 20,377 16,301
4 4 398,880 299,160 9,972 24,930 19,944
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SAE Grade 2

Bolt Size TPI Proof Load (lbs) 1 Clamp Load (lbs) 2
Tightening Torque (ft lbs)
Galv+Waxed Galv Plain
14 20 1,750 1,313 3 7 5
516 18 2,900 2,175 6 14 11
38 16 4,250 3,188 10 25 20
716 14 5,850 4,388 16 40 32
12 13 7,800 5,850 24 61 49
916 12 10,000 7,500 35 88 70
58 11 12,400 9,300 48 121 97
34 10 18,400 13,800 86 216 173
78 9 15,200 11,400 83 208 166
1 8 20,000 15,000 125 313 250
118 7 25,200 18,900 177 443 354
114 7 32,000 24,000 250 625 500
138 6 38,100 28,575 327 819 655
112 6 46,400 34,800 435 1,088 870
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ASTM A325

Bolt Size TPI Tension Tightening Torque Range (ft lbs) (Min - Max)
Min Max Galv+Waxed Plain
12 13 12,000 14,000 50 - 58 100 - 117
58 11 19,000 23,000 99 - 120 198 - 240
34 10 28,000 34,000 175 - 213 350 - 425
78 9 39,000 47,000 284 - 343 569 - 685
1 8 51,000 61,000 425 - 508 850 - 1,017
118 7 56,000 67,000 525 - 625 1,050 - 1,256
114 7 71,000 85,000 740 - 885 1,479 - 1,771
138 6 85,000 102,000 974 - 1,169 1,948 - 2,338
112 6 103,000 124,000 1,288 - 1,550 2,575 - 3,100
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ASTM A449 / SAE GRADE 5*

Bolt Size TPI Proof Load (lbs) 1 Clamp Load (lbs) 2 Tightening Torque (ft lbs)
Galv+Waxed Galv Plain
14 20 2,700 2,025 4 11 8
516 18 4,450 3,338 9 22 17
38 16 6,600 4,950 15 39 31
716 14 9,050 6,788 25 62 49
12 13 12,050 9,038 38 94 75
916 12 15,450 11,588 54 136 109
58 11 19,200 14,400 75 188 150
34 10 28,400 21,300 133 333 266
78 9 39,250 29,438 215 537 429
1 8 51,500 38,625 322 805 644
118 7 56,450 42,338 397 992 794
114 7 71,700 53,775 560 1,400 1,120
138 6 85,450 64,088 734 1,836 1,469
112 6 104,000 78,000 975 2,438 1,950
134 5 104,500 78,375 1,143 2,857 2,286
2 412 137,500 103,125 1,719 4,297 3,438
214 412 178,750 134,063 2,514 6,284 5,027
212 4 220,000 165,000 3,438 8,594 6,875
234 4 271,150 203,363 4,660 11,651 9,321
3 4 328,350 246,263 6,157 15,391 12,313
* SAE J429 grade 5 bolts do not exceed 1-1/2" diameter.
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ASTM A193 B7

Bolt Size TPI Proof Load (lbs) 1 Clamp Load (lbs) 2 Tightening Torque (ft lbs)
Galv+Waxed Galv Plain
14 20 3,350 2,513 5 13 10
516 18 5,500 4,125 11 27 21
38 16 8,150 6,113 19 48 38
716 14 11,150 8,363 30 76 61
12 13 14,900 11,175 47 116 93
916 12 19,100 14,325 67 168 134
58 11 23,750 17,813 93 232 186
34 10 35,050 26,288 164 411 329
78 9 48,500 36,375 265 663 530
1 8 63,650 47,738 398 995 796
118 7 80,100 60,075 563 1,408 1,126
8 82,934 62,201 583 1,458 1,166
114 7 101,750 76,313 795 1,987 1,590
8 105,006 78,754 820 2,051 1,641
138 6 121,300 90,975 1,042 2,606 2,085
8 129,492 97,119 1,113 2,782 2,226
112 6 147,550 110,663 1,383 3,458 2,767
8 156,687 117,515 1,469 3,672 2,938
134 5 199,500 149,625 2,182 5,455 4,364
8 218,400 163,800 - - 4,778
2 412 262,500 196,875 3,281 8,203 6,563
8 290,850 218,138 - - 7,271
214 412 341,250 255,938 4,799 11,997 9,598
8 373,801 280,351 - - 10,513
212 4 420,000 315,000 6,563 16,406 13,125
8 466,200 349,650 - - 14,569
234 4 468,500 351,263 8,050 20,124 16,100
8 515,851 386,888 - - 17,732
3 4 567,150 425,363 10,634 26,585 21,268
8 618,451 463,838 - - 23,192
314 4 674,500 505,875 13,701 34,252 27,402
8 730,550 547,913 - - 29,679
312 4 791,350 593,513 17,311 43,277 34,622
8 851,201 638,401 - - 37,240
334 4 917700 688275 21,509 53,771 43017
8 982,300 736,725 - - 46,045
4 4 1052600 789450 26,315 65,788 52630
8 1,121,950 841,463 - - 56,098
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ASTM A490

Bolt Size TPI Tension (lbs) Tightening Torque Range (ft lbs) (Min - Max)
Min Max Lubricated Plain
12 13 15,000 18,000 63 - 75 125 - 150
58 11 24,000 29,000 125 - 151 250 - 302
34 10 35,000 42,000 219 - 263 438 - 525
78 9 49,000 59,000 357 - 430 715 - 860
1 8 64,000 77,000 533 - 642 1,067 - 1,283
118 7 80,000 96,000 750 - 900 1,500 - 1,800
114 7 102,000 122,000 1,063 - 1,271 2,125 - 2,542
138 6 121,000 145,000 1,386 - 1,661 2,773 - 3,323
112 6 148,000 178,000 1,850 - 2,225 3,700 - 4,450
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ASTM A354-BD / SAE GRADE 8*

Bolt Size TPI ProofLoad (lbs) 1 ClampLoad (lbs) 2
Tightening Torque (ft lbs)
Lubricated Plain
14 20 3,800 2,850 6 12
516 18 6,300 4,725 12 25
38 16 9,300 6,975 22 44
716 14 12,750 9,563 35 70
12 13 17,050 12,788 53 107
916 12 21,850 16,388 77 154
58 11 27,100 20,325 106 212
34 10 40,100 30,075 188 376
78 9 55,450 41,588 303 606
1 8 72,700 54,525 454 909
118 7 91,550 68,663 644 1,287
114 7 120,000 90,000 938 1,875
138 6 138,600 103,950 1,191 2,382
112 6 168,600 126,450 1,581 3,161
134 5 228,000 171,000 2,494 4,988
2 412 300,000 225,000 3,750 7,500
214 412 390,000 292,500 5,484 10,969
212 4 480,000 360,000 7,500 15,000
234 4 517,650 388,238 8,897 17,794
3 4 626,850 470,138 11,753 23,507
314 4 745,500 559,125 15,143 30,286
312 4 874,650 655,988 19,133 38,266
334 4 101,4300 760,725 23,773 47,545
4 4 1,163,400 872,550 29,085 58,100
* SAE J429 grade 8 bolts do not exceed 1-1/2″ diameter.
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