Bolt Tightening Torque Charts | Coarse & Fine Threads

There are two families and four tables of Bolt Tightening Torque Guide.

Coarse Thread Series | English (Std) & Metric

 

Fine Thread Series (UNF) | English (Std) & Metric
 
 

The values presented in these tables are representative and have been compiled for the user’s benefit. Results can be influenced by any number of variables including

1) excessive lubrication
2) excessive design clamp load
3) nicked or binding threads
4) non-parallel mating surfaces 
5) inadequate torque control, to name a few.

Therefore, DeltaFlex and LORD expressly disclaims liability of any kind associated with the application of the data shown herein.

 

Coarse Thread Series | English (Std) & Metric

English Units | Coarse Thread Series - Table 1

The values presented in Table 1 - Coarse Tread Series (English Units) are representative and have been compiled for the user’s benefit. Results can be influenced by any number of variables including 1) excessive lubrication, 2) excessive design clamp load, 3) nicked or binding threads, 4) non-parallel mating surfaces, and 5) inadequate torque control, to name a few. Therefore, DeltaFlex expressly disclaims liability of any kind associated with the application of the data shown herein.

Bolt Tightening Torque - Coarse Thread Series (English Units)
Thread Size & Pitch GRADE 1 GRADE 2 GRADES 5, 5.1 & 5.2 GRADES 8, 8.1 & 8.2
Clamp Load (lb) Tightening Torque (ft-lb) Clamp Load  (lb) Tightening Torque (ft-lb) Clamp Load  (lb) Tightening Torque (ft-lb) Clamp Load  (lb) Tightening Torque (ft-lb)
6 - 32 225 0.52 375 0.86 579 1.33 818 1.88
8 - 32 347 0.95 578 1.58 893 2.44 1260 3.44
10 - 24 433 1.37 722 2.29 1116 3.53 1575 4.99
12 - 24 599 2.16 998 3.59 1543 5.55 2178 7.84
1/4 - 20 787 3.28 1312 5.47 2027 8.45 2862 11.9
5/16 -18 1297 6.75 2162 11.3 3341 17.4 4716 24.6
3/8 - 16 1918 12.0 3197 20.0 4941 30.9 6975 43.6
7/16 - 14 2631 19.2 4385 32.0 6777 49.4 9567 69.8
1/2 - 13 3512 29.3 5853 48.8 9046 75.4 12771 106
9/16 - 12 4505 42.2 7508 70.4 11603 109 16380 154
5/8 - 11 5594 58.3 9323 97.1 14408 150 20340 212
3/4 - 10 8267 103 8267 103 21293 266 30060 376
7/8 - 9 11435 167 11435 167 29453 430 41580 606
1- 8 14999 250 14999 250 33633 561 54540 909
1-1/8 - 7 18884 354 18884 354 42347 794 68670 1288
1-1/4 - 7 23983 500 23983 500 53780 1120 87210 1817
1-3/8 - 6 28586 655 28586 655 64103 1469 103950 2382
1-1/2 - 6 34774 869 34774 869 77978 1949 126450 3161
Tightening Torque = K * D * P
K = 0.2 (dry, unlubricated)
Clamp Load (P) = 75% of the Proof Load
D = Nominal Thread Size
 

 Metric Units | Coarse Thread Series - Table 2

The values presented in Table 2 - Coarse Tread Series (Metric Units) are representative and have been compiled for the user’s benefit. Results can be influenced by any number of variables including 1) excessive lubrication, 2) excessive design clamp load, 3) nicked or binding threads, 4) non-parallel mating surfaces, and 5) inadequate torque control, to name a few. Therefore, DeltaFlex and LORD expressly disclaims liability of any kind associated with the application of the data shown herein.

Bolt Tightening Torque - Coarse Thread Series (Metric Units)
Thread Size & Pitch CLASS 4.6 CLASS 5.8 CLASS 9.8 CLASS 10.9
Clamp Load (KN) Tightening Torque (N*m) Clamp Load (KN) Tightening Torque (N*m) Clamp Load (KN) Tightening Torque (N*m) Clamp Load (KN) Tightening Torque (N*m)
M6 X 1 3.41 4.09 5.73 6.87 9.80 11.76 12.5 15
M7 X 1 4.90 6.86 8.24 11.5 14.1 19.72 18.0 25
M8 X 1.25 6.20 9.93 10.4 16.7 17.8 28.55 22.8 36
M10 X 1.5 9.8 19.7 16.5 33.1 28.3 56.55 36.1 72
M12 X 1.75 14.3 34.3 24.0 57.7 41.1 98.63 52.5 126
M14 X 2 19.5 54.6 32.8 91.8 56.1 157 71.6 200
M16 X 2 26.6 85.2 44.7 143 76.5 245 97.7 313
M18 X 2.5 32.5 117 54.7 197 93.6 337 120 430
M20 X 2.5 41.5 166 69.8 279 119 478 153 610
M22 X 2.5 51.4 226 86.4 380 148 650 189 830
M24 X 3 59.8 287 101 483 172 826 220 1055
M27 X 3 77.8 420 131 706 224 1208 286 1543
M30 X 3.5 95.1 571 160 959 273 1641 349 2095
M33 X 3.5 118 776 198 1305 338 2233 432 2851
M36 X 4 138 997 233 1676 398 2868 509 3662
M39 X 4 165 1290 278 2170 476 3711 608 4739
Tightening Torque = K * D * P
K = 0.2 (dry, unlubricated)
Clamp Load (P) = 75% of the Proof Load
D = Nominal Thread Size

 

 

Fine Thread Series (UNF) | English (Std) & Metric

English Units | Fine Thread Series (UNF) - Table 3

The values presented in Table 3 - UNF Fine Tread Series (English Units) are representative and have been compiled for the user’s benefit. Results can be influenced by any number of variables including 1) excessive lubrication, 2) excessive design clamp load, 3) nicked or binding threads, 4) non-parallel mating surfaces, and 5) inadequate torque control, to name a few. Therefore, DeltaFlex and LORD expressly disclaims liability of any kind associated with the application of the data shown herein.

Bolt Tightening Torque - UNF Fine Thread Series (English Units)
Thread Size & Pitch GRADE 1 GRADE 2 GRADES 5, 5.1 & 5.2 GRADES 8, 8.1 & 8.2
Clamp Load (lb) Tightening Torque (ft-lb) Clamp Load  (lb) Tightening Torque (ft-lb) Clamp Load  (lb) Tightening Torque (ft-lb) Clamp Load  (lb) Tightening Torque (ft-lb)
6 - 40 251 0.58 419 0.96 647 1.49 914 2.10
8 - 36 365 1.00 608 1.66 940 2.57 1327 3.63
10 - 32 495 1.57 825 2.61 1275 4.04 1800 5.70
12 - 28 639 2.30 1064 3.83 1645 5.92 2322 8.36
1/4 - 28 901 3.75 1502 6.26 2321 9.7 3276 13.7
5/16 - 24 1436 7.48 2393 12.5 3698 19.3 5220 27.2
3/8 - 24 2173 13.6 3622 22.6 5597 35.0 7902 49.4
7/16 - 20 2938 21.4 4896 35.7 7567 55.2 10683 77.9
1/2 - 20 3958 33.0 6596 55.0 10194 84.9 14391 120
9/16 - 18 5024 47.1 8374 78.5 12941 121 18270 171
5/8 - 18 6336 66.0 10560 110 16320 170 23040 240
3/4 - 16 9232 115 9232 115 23779 297 33570 420
7/8 - 14 12598 184 12598 184 32449 473 45810 668
1 - 12 16409 273 16409 273 36797 613 59670 995
1-1/8 - 12 21186 397 21186 397 47508 891 77040 1445
1-1/4 - 12 26557 553 26557 553 59552 1241 96570 2012
1-3/8 - 12 32546 746 32546 746 72983 1673 118350 2712
1-1/2 - 12 39130 978 39130 978 87746 2194 142290 3557
Tightening Torque = K * D * P
K = 0.2 (dry, unlubricated)
Clamp Load (P) = 75% of the Proof Load
D = Nominal Thread Size
 

Metric Units | Fine Thread Series (UNF) - Table 4

The values presented in Table 4 - UNF Fine Tread Series (Metric Units) are representative and have been compiled for the user’s benefit. Results can be influenced by any number of variables including 1) excessive lubrication, 2) excessive design clamp load, 3) nicked or binding threads, 4) non-parallel mating surfaces, and 5) inadequate torque control, to name a few. Therefore, DeltaFlex and LORD expressly disclaims liability of any kind associated with the application of the data shown herein.

Bolt Tightening Torque - UNF Fine Thread Series (Metric Units)
Thread Size & Pitch CLASS 4.6 CLASS 5.8 CLASS 9.8 CLASS 10.9
Clamp Load (KN) Tightening Torque (N*m) Clamp Load (KN) Tightening Torque (N*m) Clamp Load (KN) Tightening Torque (N*m) Clamp Load (KN) Tightening Torque (N*m)
M8 X1 6.64 10.6 11.2 17.9 19.1 30.6 24.4 39.0
M10 X 1.25 10.4 20.7 17.4 34.9 29.8 59.7 38.1 76.2
M12 X 1.25 15.6 37.5 26.2 63.0 44.9 108 57.3 138
M14 X 1.5 21.2 59.3 35.6 100 60.9 171 77.8 218
M16 X 1.5 28.3 90.6 47.6 152 81.4 261 104 333
M18 X 1.5 36.6 132 61.6 222 105 379 134 484
M20 X 1.5 46.1 184 77.5 310 133 530 169 677
M22 X 1.5 56.4 248 94.9 418 162 714 207 912
M24 X 2 65.1 312 109 525 187 899 239 1147
M27 X 2 84.1 454 141 763 242 1306 309 1667
M30 X 2 105 632 177 1062 303 1816 387 2319
M33 X 2 129 851 217 1431 371 2449 474 3127
M36 X 3 147 1056 247 1775 422 3036 538 3877
M39 X 3 175 1362 294 2290 502 3917 641 5001
Tightening Torque = K * D * P
K = 0.2 (dry, unlubricated)
Clamp Load (P) = 75% of the Proof Load
D = Nominal Thread Size