Abstract: A bead structure for die binders which is easily convertible into either a drawbead structure or a lockbead structure includes a bead on one die binder having a generally planar roughened outer wall, a groove in the other binder, and a bead insert which is removably secured in the groove and includes a base of semi-rigid material and a series of segments secured to the base and having roughened outer walls juxtaposed to the roughened outer wall of the bead and providing a lockbead structure therewith when the binders close against a sheet metal blank. When the bead insert is removed, the bead and groove provide a drawbead structure. The sheet metal blank slides through the groove and over the roughened outer wall of the bead since the shoulders of the bead have a radius less than the radius of bending of the blank as it passes over the bead.

Abstract: Modular male and female drawbead structures comprise wafers of varying thickness which abut each other and are longitudinally wholly or partially aligned relative to each other in respective slots of die binders. The male structure has a body portion including a base wall and side walls which match and are spaced from like walls of a respective slot. A bead portion projects from an outer wall of the body portion and is joined thereby across concave shoulders. The female structure has a body portion including a base wall seating on the matching base wall of a respective slot and side walls which match and are spaced from like walls of a respective slot. A groove portion in the outer wall of the female module interfits with the bead portion and is joined to such outer wall by convex shoulders which match the concave shoulders.