1. What is the Shaft Size Calculation?

The shaft size calculation determines the minimum diameter required for a solid circular shaft to safely transmit torque without exceeding the allowable shear stress. This is fundamental in mechanical design and engineering.

2. How Does the Calculator Work?

The calculator uses the shaft diameter formula:

Where:

• \( d \) — Shaft diameter (m)
• \( T \) — Applied torque (N·m)
• \( \tau \) — Allowable shear stress (Pa)

Explanation: The equation is derived from the torsion formula for circular shafts, ensuring the maximum shear stress doesn't exceed the material's allowable stress.

3. Importance of Shaft Size Calculation

Details: Proper shaft sizing is critical for mechanical systems to ensure safety, reliability, and efficiency while preventing failure due to excessive shear stress.

4. Using the Calculator

Tips: Enter torque in Newton-meters and allowable shear stress in Pascals. Both values must be positive numbers for valid results.

5. Frequently Asked Questions (FAQ)

Q1: What units should I use for the inputs?
A: The calculator uses SI units: torque in N·m and stress in Pa. For other units, convert them first.

Q2: Does this work for hollow shafts?
A: No, this formula is specifically for solid circular shafts. Hollow shafts require a different calculation.

Q3: What's a typical allowable shear stress?
A: This varies by material. For steel, it's typically 40-60 MPa, but always consult material specifications.

Q4: Does this account for fatigue or dynamic loads?
A: No, this is for static torsion only. Dynamic loading requires additional safety factors.

Q5: What about combined loading (torsion + bending)?
A: This calculator doesn't account for combined stresses. Use appropriate formulas for combined loading scenarios.