1. What is the Torque Formula?

The torque formula T = K × F × D calculates the torque required to achieve a specific preload force in bolted joints, where T is torque, K is the torque coefficient, F is the preload force, and D is the nominal diameter.

2. How Does the Calculator Work?

The calculator uses the torque formula:

Where:

• \( T \) — Torque (Nm)
• \( K \) — Torque coefficient (dimensionless)
• \( F \) — Preload force (N)
• \( D \) — Nominal diameter (m)

Explanation: The formula accounts for the relationship between torque, preload force, and fastener size, with the torque coefficient representing friction and other factors.

3. Importance of Torque Calculation

Details: Accurate torque calculation is crucial for proper bolt tightening, ensuring joint integrity, preventing loosening, and avoiding damage from over-tightening.

4. Using the Calculator

Tips: Enter torque coefficient (typically 0.15-0.25 for standard conditions), preload force in Newtons, and nominal diameter in meters. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical torque coefficient value?
A: For standard conditions with lubricated threads, K is typically between 0.15-0.25, but varies with surface finish, lubrication, and thread type.

Q2: How does lubrication affect the torque coefficient?
A: Lubrication reduces friction and thus the torque coefficient, meaning less torque is needed to achieve the same preload force.

Q3: Why is preload force important in bolted joints?
A: Proper preload ensures the joint remains tight under operating conditions, prevents loosening from vibration, and maintains sealing pressure.

Q4: What factors affect the torque coefficient?
A: Surface finish, lubrication, thread type, material combination, and washers all influence the torque coefficient value.

Q5: When should I use a torque wrench?
A: Use a torque wrench for critical applications where precise preload is required for safety, performance, or to prevent damage to components.