# Shaft key shear and bearing stress
# Scope: Rectangular parallel key average shear and bearing pressure.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

torque = 10 N*m
shaftDiameter = 20 mm
width = 6 mm
height = 6 mm
length = 25 mm

force := 2*torque/shaftDiameter [N]
shear := force/(width*length) [MPa]
bearing := 2*force/(height*length) [MPa]

check key shear budget: shear <= 60 MPa

scenario alternative: torque = 8 N*m