Torque Wrenches Controlled Tightening,
Torque-controlled tightening method
In the case of the torque-controlled tightening procedure, the torque tool stops when pre-set final torque is reached. In this process the knowledge of the coefficient of friction is very important. Both the lubricant and the quality of the connection components and their surfaces have an influence this friction. Studies show that about 90% of the torque is used to overcome friction, only about 10% is used for elongation of the bolt.