Engineering tool · V0.7

Shaft Torsion Calculator

Calculate polar moment, nominal maximum shear stress and elastic twist for a uniform circular shaft.

Outer diameter dₒ (mm)

Inner diameter dᵢ (mm)

Torque T (N·m)

Shaft length L (mm)

Shear modulus G (GPa)

Max shear stress—

Angle of twist—

Polar moment J—

Torsional stiffness T/θ—

Enter shaft geometry.

J = π(dₒ⁴ − dᵢ⁴)/32 · τmax = Tr/J · θ = TL/(JG)

For uniform circular shafts in linear-elastic Saint-Venant torsion. Keyways, splines, shoulders, stress concentrations, noncircular sections, fatigue and critical speeds require additional analysis.