Torsion Spring Torque Calculator

How to Use the Calculator

1. Enter the mean radius (r) of your torsion spring in millimeters (mm).
2. Enter the wire diameter (d) of your torsion spring in millimeters (mm).
3. Enter the shear modulus (G) of the material used for your spring in pascals (Pa).
4. Enter the applied torque (T) in newton-millimeters (N·mm).
5. Click the "Calculate" button to compute the maximum shear stress, angle of twist, and number of coils.
6. Use the "Reset" button to clear all input fields and start over.

Understanding the Results

• Maximum Shear Stress (τ): This measures the maximum stress experienced by the spring material and is critical for ensuring the spring doesn't fail under the applied torque.
• Angle of Twist (θ): This is the angular displacement of the spring ends due to the applied torque and indicates how much the spring will twist.
• Number of Coils (N): This estimates the number of coils in the spring based on its physical dimensions and material properties.

Working Principle

The calculator uses the following formulas based on torsion mechanics:

Maximum Shear Stress: τ = (16T)/(πd³)

Angle of Twist: θ = (32T·L)/(Gπd³N)

Where:

• τ = Maximum Shear Stress (Pa)
• T = Applied Torque (N·mm)
• d = Wire Diameter (mm)
• G = Shear Modulus (Pa)
• L = Length of the spring (mm)
• N = Number of Coils

Applications

Torsion springs are used in various applications including:

• Dashboard instruments
• Watches and clocks
• Automotive components
• Office equipment
• Industrial machinery