The Chart Of Recommended Bolt Tightening Force
(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.