(Last Updated On: September 6, 2021)

The following is a recommended maximum bolt torque table to help the operator determine the maximum bolt torque to select the appropriate hydraulic torque wrench.

Strength grade4.86.88.810.912.9
Min breaking
strength
400MPa600MPa800MPa1000MPa1200MPa
MaterialGeneral structural
steel
Mechanical
construction steel
Chrome
molybdenum alloy
steel
Ni-Cr-Mo alloy steelNi-Cr-Mo alloy steel
BoltA/FTorque valueTorque valueTorque valueTorque value
MSKGMNMKGMNMKGMNMKGMNMKGMNM
162498713131181742524530294
18271312820192262563736044432
20301717026256353414947959575
22342423236348474656965380784
243630294454426058984828101994
274144432666478886312412141491457
30466058589877119117116816462011975
3350817961221195162159322822402742688
365510410231571535209204629428783523453
396013513242031986270264938037254564469
426516716382512457334327747046085645529
457020920453133068417409058757527046903
487525124613763691502492170669218478305
52803253181487477164963629138946109510736
5685404395660559348077912113511127136213352
60905044932755739810069864141513871169816645
649560859609128940121611920171016762205220115
681007387230110710845147514460207520335245024401
721058858669132713003176917337248824381298529257
7611010501028715741543020992057329522893134717
8011512341209418511814124682418834713401440815
851201493146362240219532987292714116349395
901301787175102680262663573350214924859098
100145248424341372636512486836846082152
110155334232751491266550192111110533
1201754378429026435485805120663144795
125180486837302497366136920164304

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 M52 grade 8.8 bolt, the tightening torque is 6362*(70-80)% = 4453-5090Nm.
The loosening torque should be 1.5-2.5 times of tightening torque.