MP-24 · SHAFTS AND JOINTS
Key and Keyway Screen
Screen a parallel key for nominal shear and bearing stress from torque, shaft diameter, key width, height, length, and entered limits.
Preliminary design support. Your inputs and results stay in this browser.
WHAT THIS SCREEN ANSWERS
A key transmits torque through a small contact area, which makes geometry and fit important. The shaft torque becomes a tangential force at the shaft radius. That force can shear the key or bear against the key and hub. This screen separates those nominal mechanisms before a standard key size is assumed to solve the connection.
Enter shaft torque and diameter with the actual key width, height, engaged length, and user-supported limits. MechPlane converts torque to tangential force, then calculates nominal key shear and bearing stress. The page names each ratio independently because a key can look acceptable in one mode and be marginal in the other.
Keyways reduce shaft section and introduce stress concentrations. Hub material, key fit, contact distribution, fretting, reversal, fatigue, corrosion, assembly, and manufacturing tolerances change the real behavior. A standard key table identifies geometry. It does not remove the need to check the shaft, hub, and duty around the keyway.
Use this screen to compare early key proportions and identify a governing nominal condition. Confirm applicable key standards, keyway dimensions, shaft and hub material, fit, fatigue, stress concentration, manufacturing process, and supplier or drawing requirements before release.