Sheet Metal Stamping: Blanks, Drawn Cans and Washers

Stamping turns coil into parts at press speed. The coil is uncoiled, straightened and fed into a press whose die cuts and shapes it: blanking cuts the outline, piercing punches holes, forming bends, drawing pulls a flat blank into a cup. A washer is one blank pierced in the middle. A drink can is a blank punched from stiff cold-rolled aluminium sheet (typically alloy 3104-H19 or 3004-H19), drawn into a cup about three inches across, then pushed through ironing rings that stretch and thin the wall. Its end is stamped separately from alloy 5182-H48 coil; a conversion press forms the rivet button, scores the opening and fits the tab.