a process for forming sheet metal material having a yield strength and tensile strength which are sensitive to small changes in temperature at ambient conditions , wherein an unheated sheet metal workpiece is drawn between a concave die cavity and a mating convex punch by relative movement therebetween into the internal configuration of the die , and wherein the workpiece is selectively cooled in those areas which are susceptible to breakage . cooling may be effected by cooling portions of the punch , or in complex part designs by cooling localized portions of the die , or both . the amount of cooling is relatively slight and may be only that required to remove heat generated by plastic deformation of the workpiece in the areas susceptible to breakage .