1. What is Shaft Diameter Calculation?

The shaft diameter calculation determines the minimum diameter required for a shaft to safely transmit torque without exceeding the allowable shear stress. It's a fundamental mechanical engineering calculation for shaft design.

2. How Does the Calculator Work?

The calculator uses the shaft diameter formula:

Where:

• \( d \) — Shaft diameter (meters)
• \( T \) — Torque (Newton-meters)
• \( \tau \) — Allowable shear stress (Pascals)

Explanation: The equation calculates the minimum diameter needed to prevent shear failure under applied torque, considering the material's shear strength.

3. Importance of Shaft Sizing

Details: Proper shaft sizing is critical for mechanical system reliability. Undersized shafts may fail, while oversized shafts are unnecessarily heavy and expensive.

4. Using the Calculator

Tips: Enter torque in Nm and allowable shear stress in MPa. The calculator returns the minimum diameter in millimeters. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What safety factor should I use?
A: Typical safety factors range from 1.5 to 3 depending on application criticality and load certainty.

Q2: How does material affect the calculation?
A: Different materials have different allowable shear stresses. Steel typically ranges 40-100 MPa.

Q3: What about combined loading?
A: For shafts with bending and torsion, use equivalent torque or von Mises stress criteria.

Q4: Should I consider keyways?
A: Keyways reduce shaft strength. Increase calculated diameter by 25% or use specific keyway factors.

Q5: How precise is this calculation?
A: It provides theoretical minimum. Final size should consider standard available sizes and other factors like deflection.