Torsional Deflection Hollow Cylinder Formula

Equation for calculate torsional deflection hollow cylinder is,

α = L T / GI_o

Where,
T = Torque (N-mm, in-lb)
L = Length of Shaft (mm, in)
G = Shear Modulus of rigidity (Mpa, psi)
I_o = Second Moment of Inertia (mm4, in4)