Wire drawing machine
In a wire-drawing process, a coarse wire previously created by forging and nowadays by rolling, is pulled in its cold state through the progressively smaller aperture of a drawing iron, drawing die or roll stand. It becomes longer and thinner, without any material being lost. From production pass to production pass, it is drawn through progressively smaller apertures, until the wire finally has the desired dimension. In industrial manufacturing operations, the wire is drawn through the drawing die by what is called a drawing capstan. Modern-day wire drawing machines (multiple passes) have up to 31 stages and are very sophisticated in terms of I&C, since all drawing stages are run in conjunction. The wire is drawn in either a wet or dry drawing process. In wet drawing, the wire is wetted with a drawing agent or oil. This process downsizes the friction in the drawing die, keeps the wire cool, and thus reduces strain hardening. This leads to better wire surfaces and enables a higher drawing speed to be achieved. Since the machine concerned has to be manufactured in a liquid-tight construction, it is often more expensive.