engineering

Key and Keyway Calculator

Calculate shear and compressive stress in shaft keys and look up standard ANSI key sizes by shaft diameter

Key and Keyway Calculator

Calculate shear and compressive stresses in shaft keys with standard ANSI key size lookup.

Formulas

τ = 2T / (d · w · L)   (shear in key)
σ = 4T / (d · h · L)   (compressive/bearing)
FOS_shear = τ_allow / τ   FOS_comp = σ_allow / σ

ANSI Recommended Key for d = 50.0 mm

w × h = 14 × 9 mm (shaft range 4450 mm)

Results

Shear Stress τ

28.57 MPa

FOS = 2.800

Compressive Stress σ

88.89 MPa

FOS = 1.800

Governing FOS (compression controls)

1.800

How to Use This Calculator

1

Enter your input values

Fill in all required input fields for the Key and Keyway Calculator. Most fields include unit selectors so you can work in your preferred unit system.

2

Review your inputs

Double-check that all values are correct and that you have selected the right units for each field. Incorrect units are the most common source of calculation errors.

3

Read the results

The Key and Keyway Calculator instantly computes the output and displays results with units. All calculations happen in your browser — no loading time and no data sent to a server.

Formula Reference

Key and Keyway Calculator Formula

See calculator inputs for the governing equation

Variables: All variables and their units are labeled in the calculator interface above.

When to Use This Calculator

  • Use the Key and Keyway Calculator when solving homework or exam problems that require quick numerical verification of your hand calculations.
  • Use it during the design phase to rapidly iterate on parameters before running detailed finite element simulations.
  • Use it when reviewing a colleague's calculation or checking a vendor's data sheet for plausibility.
  • Use it to generate reference data for a technical report or presentation without manual computation.

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