1. What is Screw Torque Calculation?

Screw torque calculation determines the rotational force required to achieve a specific clamp force in threaded fasteners. It's essential for proper bolt tightening and preventing joint failure in mechanical assemblies.

2. How Does the Calculator Work?

The calculator uses the screw torque formula:

Where:

• \( T \) — Torque (N·m)
• \( F \) — Clamp force (N)
• \( L \) — Lead (m)
• \( K \) — Friction factor (dimensionless)

Explanation: The formula calculates the torque required to overcome friction and generate the desired clamp force in a threaded fastener system.

3. Importance of Torque Calculation

Details: Accurate torque calculation ensures proper joint integrity, prevents overtightening (which can damage threads) and undertightening (which can cause joint failure), and maintains safety in mechanical assemblies.

4. Using the Calculator

Tips: Enter clamp force in newtons (N), lead in meters (m), and friction factor (typically 0.1-0.3 for lubricated threads). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical friction factor value?
A: For lubricated steel threads, K is typically 0.15-0.25. For dry threads, it can be 0.3-0.5. Always consult manufacturer specifications.

Q2: How does lead differ from pitch?
A: Lead is the axial distance a screw travels in one complete revolution. For single-start threads, lead equals pitch. For multi-start threads, lead = pitch × number of starts.

Q3: Why is torque calculation important?
A: Proper torque ensures joint integrity, prevents bolt failure, and maintains safety in mechanical systems from automotive to aerospace applications.

Q4: What affects friction factor?
A: Surface finish, lubrication, thread type, material combination, and temperature all influence the friction factor value.

Q5: Can this formula be used for all thread types?
A: This simplified formula works for standard threads. Special thread forms or extreme conditions may require more complex calculations.