Cold drawn black wire
During the process of making cold drawn steel wire, steel is passed through a drawing die at room temperature. A gripping device pulls the undrawn steel coil through the die to increase the length, reduce the cross width, and form the steel into the desired shape. Multiple passes through a die are necessary to shape the cold wire into the desired shape and properties.
Between each pass through the die, the wire will typically be annealed to increase the wire’s ductility and to alter the characteristics of the steel. The steel can be annealed before, during or following passes through the die – all depending on the end specifications of the steel wire.