(Last Updated On: September 6, 2021)

The following is a recommended maximum torque table for bolt tensioners to help the operator determine the torque of hydraulic bolt tensioners to select the right bolt tensioners.

The datas are mainly suitable for bolt tensioner and hydraulic nut.

Strength grade 4.8 6.8 8.8 10.9 12.9
Min breaking strength 400MPa 600MPa 800MPa 1000MPa 1200MPa
Material General structural
steel		 Mechanical
construction steel		 Chrome
molybdenum
alloy steel		 Ni-Cr-Mo alloy steel Ni-Cr-Mo alloy steel
Bolt A/F Tightening Force
M S (KN)
16 24 30 45 60 85 102
18 27 37 55 74 104 125
20 30 47 71 94 132 159
22 34 58 87 117 164 197
24 36 68 102 135 190 228
27 41 88 132 176 248 298
30 46 108 161 215 303 363
33 50 133 200 266 375 449
36 55 157 235 314 441 529
39 60 187 281 375 527 632
42 65 215 323 430 605 726
45 70 251 376 502 705 846
48 75 283 424 566 796 955
52 80 338 506 675 949 1139
56 85 390 585 780 1096 1315
60 90 454 680 907 1275 1531
64 95 514 771 1028 1445 1734
68 100 587 880 1173 1650 1980
72 105 664 996 1329 1868 2242
76 110 747 1120 1494 2100 2520
80 115 834 1251 1668 2346 2815
85 120 950 1425 1900 2672 3206
90 130 1073 1610 2147 3019 3623
100 145 1343 2014 2686 3777 4533
110 155 1643 2464 3285 4620 5544
120 175 1973 2959 3945 5548 6657
125 180 2149 3223 4298 6043 7252

Attention:
The data in the chart is measured under 60% yield limit of the bolt, the recommended tightening torque is
70-80% of above data.
For example, for M42 grade 10.8 bolt, the tightening torque is 605*(70-80)% = 423.5-484KN.