Torsion Calculator
Calculate angle of twist in shafts.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Request a ToolHow to Use the Torsion Calculator
Enter torque, shaft length, shear modulus, and polar moment of inertia.
- Enter values.
- Read the result in degrees and radians.
About the Torsion Calculator
Torsion occurs when a shaft or member is twisted by an applied torque. The angle of twist depends on the torque, shaft length, material shear modulus, and cross-section geometry (polar moment of inertia). Engineers must ensure that the angle of twist stays within acceptable limits and that the maximum shear stress does not exceed the material's shear strength.
Frequently Asked Questions
What is the polar moment of inertia?
The polar moment of inertia (J) measures a cross-section's resistance to twisting. For a solid circle, J = pi*d^4/32. For a hollow circle, J = pi*(D^4 - d^4)/32.
What is typical acceptable twist?
Typical limits are 0.25 to 1 degree per meter of shaft length, depending on the application. Precision machinery may require much tighter limits.
How does shaft diameter affect torsion?
J is proportional to the fourth power of diameter. Doubling the diameter increases torsional stiffness by 16 times.