Classification of Processes

The traditional division of metal-forming operations into cold and hot has lost a great deal of its rigidity in the last decade or so. Development of metal-forming technology has enabled us to carry out a number of operations in either range or even, as in the case of, say, warm extrusion, between the ranges. The incidence of redundancy, depending as it does on both the tool design and the properties of the worked material, is not necessarily a constant factor in a forming operation. A division of processes into hot and cold groups does not therefore provide a particularly helpful guide to assessing a priori the potential effects of redundancy.