1. What is Metric Screw Torque Calculation?

Metric screw torque calculation determines the appropriate tightening torque for metric screws and bolts based on the torque coefficient, nominal diameter, and axial force. Proper torque application is essential for ensuring secure fastening without damaging the components.

2. How Does the Calculator Work?

The calculator uses the metric screw torque formula:

Where:

• \( T \) — Torque (N·m)
• \( K \) — Torque coefficient (dimensionless)
• \( D \) — Nominal diameter (mm)
• \( F \) — Axial force (N)

Explanation: The formula calculates the required torque based on the screw's characteristics and the applied force, ensuring proper fastening without over-tightening.

3. Importance of Torque Calculation

Details: Accurate torque calculation is crucial for maintaining joint integrity, preventing loosening under vibration, avoiding thread stripping, and ensuring proper clamping force in mechanical assemblies.

4. Using the Calculator

Tips: Enter the torque coefficient (typically 0.2 for dry steel, 0.15-0.18 for lubricated), nominal diameter in millimeters, and axial force in Newtons. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical torque coefficient value?
A: For dry steel on steel, K is typically around 0.2. For lubricated threads, K ranges from 0.15 to 0.18. Specific applications may require different coefficients.

Q2: Why is proper torque important?
A: Proper torque ensures sufficient clamping force without damaging threads, prevents loosening from vibration, and maintains joint integrity under load.

Q3: How does lubrication affect torque requirements?
A: Lubrication reduces friction, requiring less torque to achieve the same clamping force. This is why lubricated fasteners have a lower K value.

Q4: What happens if I over-torque a fastener?
A: Over-torquing can stretch the bolt beyond its yield point, strip threads, damage the mating surfaces, or cause premature failure under load.

Q5: Are there industry standards for torque values?
A: Yes, various industry standards (ISO, DIN, ASME) provide recommended torque values for different fastener grades, materials, and applications.