1. What is Helical Torsion Spring Stress?

The helical torsion spring stress equation calculates the maximum shear stress in a helical torsion spring subjected to a load. This stress value is crucial for determining if the spring will function properly without failure.

2. How Does the Calculator Work?

The calculator uses the helical torsion spring stress equation:

Where:

• \( \tau \) — Shear stress (Pa)
• \( P \) — Applied load (N)
• \( D \) — Mean coil diameter (m)
• \( d \) — Wire diameter (m)

Explanation: The equation shows that stress increases with larger loads and coil diameters, but decreases dramatically with larger wire diameters (cubed relationship).

3. Importance of Stress Calculation

Details: Calculating spring stress is essential for spring design to ensure the material can withstand the applied loads without permanent deformation or failure.

4. Using the Calculator

Tips: Enter load in newtons (N), diameters in meters (m). All values must be positive numbers. For accurate results, use consistent units.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical safe stress range for spring steel?
A: For music wire, working stresses are typically 40-50% of the material's tensile strength, around 400-700 MPa depending on the alloy.

Q2: How does coil diameter affect spring performance?
A: Larger coil diameters increase stress for the same load, but provide greater angular deflection per unit length.

Q3: What happens if stress is too high?
A: Excessive stress can cause permanent set (loss of spring properties) or immediate failure through fracture.

Q4: Does this equation account for stress concentration?
A: No, the basic equation doesn't include stress concentration factors which are important at the ends where loads are applied.

Q5: Can this be used for non-circular wire?
A: No, this equation is specifically for round wire. Rectangular wire requires a different formula.