Abstract: A punch and die assembly including a punch having an outer surface conforming generally to a configuration desired for a sheet metal part to be produced and adapted for rectilinear movement in a given direction between retracted and extended positions, the punch having a rear portion with a cross-section of given width and a front portion with a cross-section of predetermined width greater than the given width; and a die body defining a cavity comprising an outer portion defining an opening for receiving the punch and an inner portion communicating with the outer portion. The inner portion has a cross-section with substantially uniformly spaced side walls dimensioned so as to closely accommodate the front portion of the punch and a sheet metal workpiece, and to provide between said rear portion of the punch and the side walls a gap greater than twice the thickness of the workpiece when the punch is in its extended position within the outer portion of said cavity.

Abstract: A die for use with a punch for bending flat metal stock and including a body defining a support surface adapted to support a piece of flat metal stock, a cavity disposed in a path of movement of the punch and intersecting and projecting below the support surface, and a stop surface forming a bottom wall of the cavity and having first and second surface portions; and a mounting retained by the body. A first elongated die bar is supported by the mouting for both translational and pivotal movement on a first axis in the cavity on one side of the path of movement; the first die bar defining upper and lower surfaces having a wedge shaped cross-section. A second elongated die bar also is supported by the mounting for both translational and pivotal movement on a second axis in the cavity on an opposite side of the path of movement; the second die bar defining upper and lower surfaces having a wedge shaped cross-section. This combination eliminates scoring during the bending of flat metal stock.