Elastic stresses due to torque transmitted through the prismatic part of keyed connections part I: Effect of different fits and friction on standard shapes

Photoelastic models of transverse sections through British Standard metric and inch keyed shafts and hubs (outside diameter = 2 × shaft diameter) have been loaded in torsion. Models with five different combinations of fits of shaft in hub, key in shaft, and key in hub, with three different surface conditions have been analysed over a large range of torques. Stress concentrations occurred at the six contact positions where there are discontinuities of profile of the chamfered key or of the shaft. Normalized peak stresses are presented for all tests and the effects of the controlled variables are discussed.