Torsion (mechanics)

Twisting of an object due to an applied torque

In solid mechanics, torsion is the twisting of an object caused by an applied torque. It may be described as an angular deformation, measured by the rotation of a cross-section from its undeformed position. Torque is commonly expressed in newton metres (N·m) or foot-pound force (ft·lbf), while the resulting torsional shear stress is expressed in pascals (Pa) or pounds per square inch (psi).

From Wikipedia, under CC BY-SA. More on occurri.