The torsion equation is derived on the basis of following assumptions:

☛ > The shaft material is uniform, throughout the shaft.

☛ > Even after loading the shaft circular remains circular.

☛ > After the application of torques the plain section of a shaft remains plain.

☛ > Any twist that occurs in the shaft remains uniform and constant.

☛ > After the application of torque the distance between any two cross-sectional references remains constant.

☛ > The elastic limit value of a shaft is never exceeded even after the