1. What is the Screw Force Formula?

The screw force formula calculates the axial force generated from applied torque in screw mechanisms. It accounts for the mechanical advantage provided by the screw's geometry and the friction between contacting surfaces.

2. How Does the Calculator Work?

The calculator uses the screw force formula:

Where:

• \( F \) — Axial force (N)
• \( T \) — Applied torque (Nm)
• \( r \) — Radius of the screw (m)
• \( \alpha \) — Lead angle (degrees)
• \( \phi \) — Friction angle (degrees)

Explanation: The formula calculates the axial force generated when torque is applied to a screw, considering both the mechanical advantage from the screw geometry and the friction losses.

3. Importance of Screw Force Calculation

Details: Accurate screw force calculation is crucial for designing mechanical systems, determining clamping forces, calculating load capacities, and ensuring proper functioning of screw-based mechanisms.

4. Using the Calculator

Tips: Enter torque in Nm, radius in meters, lead angle and friction angle in degrees. All values must be valid positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the lead angle in screw mechanics?
A: The lead angle is the angle between the thread helix and a plane perpendicular to the screw axis, representing the steepness of the thread.

Q2: How is friction angle determined?
A: Friction angle is calculated from the coefficient of friction (μ) using φ = arctan(μ). It represents the angle at which sliding occurs.

Q3: When is this formula applicable?
A: This formula applies to screw jacks, power screws, and other screw mechanisms where torque is converted to axial force.

Q4: What are typical values for friction angle?
A: Friction angle varies with materials. For steel on steel, it's typically 8-12 degrees; for lubricated surfaces, it can be as low as 2-6 degrees.

Q5: Can this formula be used for reverse calculation?
A: Yes, the formula can be rearranged to calculate required torque for a given axial force: T = F × r × tan(α + φ).