Engineering & Construction
Bolt Torque Calculator
Estimate bolt torque as K × preload × diameter. Preload is in kilonewtons and diameter is in millimetres, so the torque is in newton-metres.
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How to use the Bolt Torque Calculator
- 1Enter the nut factor K. A dry steel thread is often near 0.2.
- 2Enter the preload and the nominal diameter.
- 3Read the torque.
Questions
What is K?
A factor for the friction in the thread and under the nut. Lubrication changes it. Use the K from the bolt supplier when you have it.
Is this a tightening procedure?
No. It is the formula T = KFD with the numbers you enter.