Drawn steels are made through a specific technique called wire drawing, which is a technological operation involving the processing of various metal alloys, especially steel. Through a shaping process, drawing changes the shape of the raw material through plastic deformation thanks to the action of forces impressed by equipment and dies.
How drawn steels are obtained
The technique for obtaining drawn steels is based on an important characteristic: the ductility of the metal.
Specifically, the product is pulled through one or more calibrated holes having progressively decreasing cross sections. Typically, this is a shaping operation performed in cold (i.e., cold drawing) with specific machinery called drawing machines or multiple drawing machines (in case of multiple reduction phases).
Essentially, the technological operation of drawing allows the material to be modified until the desired shape and section are achieved. This technique is also used when it is necessary to reduce tolerances or work harden the metal.
Characteristics of drawing:
- The volume of the material is unchanged
- No material is removed
- Steel work hardens
- Good surface finishes are obtained
- Products with precise dimensions and low tolerances are obtained
In addition, according to classifications of deforming processes, drawing belongs to the:
- Cold processes because usually the initial wire or bar are not preheated
- Massive forming processes, which differ from thin sheet forming processes
- Secondary machining processes (such as bending) because it transforms primary machining products (forged, rolled, extruded, drawn) into finished or semi-finished products. Machined products undergo minor changes in shape usually through bending (to form springs, hooks, staples, etc.) or other finishing operations (e.g., to make screws or the tips of fish hooks).
The purpose of drawing is thus to obtain tubes, wires, rods, and profiles of various shapes with high dimensional accuracy and good surface finish.