Cold drawing machine is a mechanical process that allows metal bars or rods to be drawn or extruded into a desired shape. The process works by reducing the cross-sectional size of the material using pressure applied to the workpiece. This reduces the tensile strength of the material but increases its ductility. This is a common method for producing the curved or oval shapes required by various industrial applications.
The cold drawing process also increases the accuracy of the shaped cross-sections. This is because it is easier to control the shape of the finished product with cold drawing than hot extrusion. Cold drawn cross-sections are also less expensive than hot extruded products because they do not require costly alloys to meet strength requirements.
In general, a metal bar or rod is drawn several times to achieve the final desired shape and tolerances. This process is called multi-pass drawing and may require the use of a fixed plug (a metal piece that fits into the hole in a die to help control the wall thickness) or a floating plug (a metal taper inserted into the end of a tube to adjust the inside diameter). The redrawn material is generally annealed between each drawing pass to remove cold work and increase ductility.
This process is not only suitable for carbon and low-alloy steel but can be used to draw a wide variety of materials including copper and aluminum. It can even be used to draw titanium and zirconium alloys, although these are typically only produced in low-volume, specialized processes such as pilgering or tube rolling.
During the cold drawing process, the material is drawn through a series of dies of decreasing size. The force applied to the workpiece during each drawing pass is measured with strain gauges and recorded by automation systems. The data is then used to calculate the energy-power parameters of the drawing process.
HOREN manufactures a variety of cold drawing machines including chain-type drawbench models. They are designed for the drawing of round, hexagonal & square steel tubes and rods that require re-sizing, precision and strict tolerances for a range of industrial applications. These models can be supplied with partial automation to include a pneumatic mandrel lifting and forward system, tube pusher and discharging arms that can be optionally equipped to the drawbench. Other capabilities include rotary air benders to form sharp angles & radius bends as well as cutting up to 500 mm dia., lathe cutting for up to 1000 mm between centers, milling up to 500 mm x 800 mm x 1056 mm, wire EDM, surface, cylindrical & jig grinding, band & circular sawing and EDI using AutoCAD(r) & inspection.