Engineering lab · Interactive tool

Shaft Torsion + Power Calculator.

Convert torque, power, and rotational speed while screening a solid or hollow circular shaft for elastic stress and twist.

Circular shaft / elastic torsion + transmitted power

Live calculation

01Drive input

02Shaft + material

Circular shaft in torsionA circular shaft transmits torque between two ends.TORQUETORQUELENGTH
Elastic circular-shaft torsionτ = Tr / J; θ = TL / (JG)

Shaft results updated. Torque 100 newton meters. Maximum shear 32.59 megapascals. Yield factor of safety 6.55.

Torque100 N·m12.57 kW at 1,200 rpm
Maximum shear32.59 MPaouter fiber
Angle of twist1.418°over 750 mm
Yield factor of safety6.55J = 38,349.52 mm⁴
Revision1.2
AuthorJared Maffucci
Last technical review23 July 2026
Input guardrailsFinite values; nonnegative magnitudes; physical geometry and material domains enforced
UsePreliminary engineering judgment only
Variable definitions
  • T: torque
  • P: power
  • n: speed
  • J: polar moment
  • G: shear modulus
  • L: shaft length
Hand-verified examples
  • 100 N·m mode: classical stress and twist
  • 5 kW at 1500 rpm: 31.831 N·m torque
Change log · revision 1.2

Added visible variables, two verification examples, and an experience connection. Calculation method is unchanged.

Related engineering capability

Stress is only one shaft-design constraint

The calculator uses classical elastic torsion for a prismatic circular shaft. It is useful for identifying whether strength, stiffness, or packaging is likely to control the first iteration.

Real shafts usually need combined bending and torsion, stress-concentration, fatigue, bearing, keyway, spline, critical-speed, transient-load, and manufacturing checks.

Escalate the model when

  • Shoulders, grooves, keyways, or splines are present
  • Bending and torsion act together
  • Torque is cyclic, reversing, impulsive, or uncertain
  • Critical speed, vibration, or alignment can control
  • Fatigue life or safety consequence is significant

Direct conversation

Review the product, the available evidence, and the decision blocking progress.

Send a concise, non-confidential brief. You will work directly with Jared from the first review through final handoff.

Discuss a Product