1. What is Screw Torque Calculation?

Screw torque calculation determines the rotational force required to achieve proper preload in threaded fasteners. It ensures secure connections while preventing damage from over-tightening or under-tightening.

2. How Does the Calculator Work?

The calculator uses the screw torque formula:

Where:

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

Explanation: The formula calculates the torque required to achieve a specific preload force based on the screw's diameter and material properties.

3. Importance of Screw Torque Calculation

Details: Proper torque calculation is essential for mechanical integrity, preventing joint failure, ensuring safety, and maintaining optimal performance in assembled structures.

4. Using the Calculator

Tips: Enter torque coefficient (typically 0.15-0.25 for standard bolts), preload force in Newtons, and nominal 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, K typically ranges from 0.15 to 0.25, but varies based on lubrication, surface finish, and material.

Q2: How do I determine preload force?
A: Preload is typically 60-75% of the bolt's proof load, which can be calculated from material properties and cross-sectional area.

Q3: Why is accurate torque important?
A: Under-torquing can lead to joint loosening, while over-torquing can cause bolt stretching, thread stripping, or fracture.

Q4: Does lubrication affect torque calculation?
A: Yes, lubrication significantly reduces the torque coefficient, requiring less torque to achieve the same preload force.

Q5: Can this formula be used for all fastener types?
A: While the basic formula applies to most threaded fasteners, specialized fasteners may require modified calculations.