VALICALC · ENGINEERING WORKFLOW
Shaft torque and key geometry check
Convert power and RPM to shaft torque, compare tangential force at a radius, and look up a documented key geometry for a measured shaft.
Start this workflowWhat do I need to know first?
- Mechanical power delivered at the shaft and rotational speed
- Effective force radius for the force check
- Measured shaft diameter and the applicable shaft/key convention
Goal and model boundaries
Connect torque and transmitted force to a key-size lookup without claiming to design a shaft, key or bearing.
- Torque is steady operating torque; peak, reversing and fatigue loads need separate review.
- Keyway geometry is not a key shear/bearing-stress calculation. Shaft stress, bearing selection and life are outside the available tools.
Calculate operating torque
Enter mechanical power and the shaft RPM.
T = P/ω, with ω = 2πn/60.
- Expected output
- Torque at the stated shaft speed.
- Next step
- Use the torque and actual load radius for the force check.
Check tangential force
Enter operating torque and the effective radius.
F = T/r; keep torque and radius units consistent.
- Expected output
- A tangential force estimate at that radius.
- Next step
- Use the measured shaft diameter for a key geometry lookup; assess stress separately.
Look up key geometry
Search the measured shaft diameter and check the exclusive/inclusive range limits.
The bounded table maps shaft ranges to listed key widths and heights.
- Expected output
- A nominal key geometry and its documented shaft range.
- Next step
- Verify the drawing, material, key length, tolerances and structural design independently.
Units and context
- Use shaft power, not electrical input power, when calculating transmitted torque.
- Radius is half the diameter; N·m and N·mm differ by 1000.
Common mistakes to avoid
- Using diameter in a radius input
- Selecting a key from a shaft-range boundary incorrectly
- Treating a dimensional lookup as structural approval
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