Shear Keys:
To connect the shaft having the hub or flywheel, shear keys are utilized. The torque in the shaft transferred to flywheel by means of shear keys.
Figure: Shear Keys
Let L = length of the key
b = width of the key
Area of key = L b
τ1 = Shear stress in the key
Force in the key τ1 = Lb
Moment about centre = (τ L b) R
∴ T = (τ1 L b R)