Standard DTI FAQs
Torque control
- How much torque does it take to tension a bolt
with a DTI?
- You have Twist-Off or TC bolts on a job, and yet the engineer has specified that DTI's must be used. Can both TC bolts and DTI's be used together? See twist-off bolts
How much torque does it take to tension a bolt with a DTI?
Amazingly, the same torque as it would take without a DTI.(see torque requirements) Torque resistance can vary as much as +/- 30% at the same tension even within a single lot of bolts and nuts. Nut grade, the condition of the threads, the fit of the nut, coatings, thread deterioration, all conspire to make the torque resistance highly variable. In many countries, torque control is not a recognized method of installing bolts. All of this is why DTI's are used. They are very "stupid", compressing in proportion to the applied tension, which is what is wanted, and not in proportion to the torque resistance of the bolt assembly which can be high or low. Also see tool capacity
