1. What is the Bolt Torque to Tension Formula?

The bolt torque to tension formula calculates the axial force (tension) developed in a bolt when a specific torque is applied. This relationship is fundamental in mechanical engineering and bolted joint design to ensure proper clamping force.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( F \) — Tension force (N)
• \( T \) — Applied torque (Nm)
• \( K \) — Torque coefficient (dimensionless)
• \( D \) — Bolt diameter (m)

Explanation: The formula converts rotational torque into axial tension force, accounting for the bolt diameter and friction characteristics through the torque coefficient.

3. Importance of Tension Calculation

Details: Accurate tension calculation is crucial for ensuring bolted joints have sufficient clamping force to withstand operational loads while preventing over-tightening that could damage components or cause bolt failure.

4. Using the Calculator

Tips: Enter torque in Nm, torque coefficient (typically 0.15-0.25 for standard bolts), and bolt diameter in meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical torque coefficient value?
A: For standard steel bolts with lubrication, K is typically between 0.15-0.25. The exact value depends on surface finish, lubrication, and thread condition.

Q2: Why is bolt tension important?
A: Proper bolt tension ensures joint integrity, prevents loosening under vibration, and maintains sealing pressure in gasketed joints.

Q3: How accurate is this calculation?
A: The calculation provides an estimate. Actual tension can vary due to friction variations, lubrication consistency, and measurement accuracy.

Q4: Can this formula be used for all bolt types?
A: The formula works for standard bolts but may need adjustment for specialized fasteners or unique thread designs.

Q5: What units should be used?
A: Use consistent SI units: torque in Newton-meters (Nm), diameter in meters (m), and the result will be in Newtons (N).