The term "straightening" covers the actions and measures needed to eliminate process-induced curvatures in the process material in order to produce a condition of straightness, levelness or defined curvature.
The book places straightening within the taxonomy of manufacturing processes. Forming — defined as a manufacturing process based on the plastic transformation of a body — divides into forming by compressed air, by tensile force, by tensile and compressive force, by bending force, and by shear force. Straightening belongs, together with bending, to forming by bending force: a workpiece's faulty shape (a curved product to be straightened) is eliminated or reduced, and plastic forming is required.
See Also
Adapted from “"We do it straight" — Wire Straightening”, p. 161 (ISBN 3-00-005897-4).