1. What is Screw Clamping Force?

Screw clamping force (F) is the axial force generated when a torque is applied to a screw or bolt. It represents the compressive force that holds joined materials together and is crucial for maintaining joint integrity and preventing loosening.

2. How Does the Calculator Work?

The calculator uses the screw clamping force formula:

Where:

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

Explanation: The formula calculates the axial clamping force generated from the applied torque, considering the screw diameter and friction coefficient.

3. Importance of Clamping Force Calculation

Details: Accurate clamping force calculation is essential for proper joint design, preventing bolt failure, ensuring adequate preload, and maintaining structural integrity in mechanical assemblies.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range for torque coefficient K?
A: For standard bolts, K typically ranges from 0.15 to 0.25, but can vary based on lubrication, surface finish, and thread condition.

Q2: Why is clamping force important in bolted joints?
A: Proper clamping force prevents joint separation, reduces vibration loosening, and ensures the joint can withstand operational loads without failure.

Q3: How does lubrication affect the torque coefficient?
A: Lubrication reduces friction, which decreases the torque coefficient (K), resulting in higher clamping force for the same applied torque.

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

Q5: When should this formula not be used?
A: This simplified formula may not be accurate for very high precision applications, specialized fasteners, or when significant elastic interactions occur in the joint.