Bolt Torque Calculator: Ensure Precision Fastener Tightening

Calculate Your Bolt Torque Instantly

A dimensionless coefficient accounting for friction (typical range 0.1 - 0.25).
The nominal diameter of the bolt.
The desired axial clamping force on the joint.

Use our advanced Bolt Torque Calculator to quickly determine the exact tightening force needed for any fastener. Input your nut factor, bolt diameter, and target preload to ensure optimal joint integrity and prevent under or over-tightening. Essential for engineers, mechanics, and DIY enthusiasts.

Formula:

The standard formula for calculating bolt torque is:

T = K × F × D

  • T: The resulting Torque (e.g., N·m or ft·lb)
  • K: The Nut Factor or Coefficient of Friction (dimensionless, typically between 0.1 and 0.25)
  • F: The desired Target Bolt Preload or Clamping Force (e.g., Newtons or lbf)
  • D: The Nominal Bolt Diameter (e.g., meters or inches for unit consistency, input as mm or in for convenience)

This formula accounts for the friction present in the bolted joint, crucial for accurate tightening.

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