Cold drawing machine is a process for reducing the diameter of metal rods and bars. This method is used to provide a more precise and accurate finish than extruded products, while still providing strict tolerances for various industrial applications. It can be used on round, hexagonal, square, and rectangular rods and bars, resulting from the cold rolling or extrusion processes.
The first step in cold drawing involves submerging the steel bars in a lubricant. This helps the steel bars pass through the die more easily. The steel bars are then forced through the die, which stretches them to the desired size. The steel bars are manipulated by applying pressure to the lead ends. The drawing process can take several passes to get the desired size. The final product is more precise than hot-extruded products, and the surface has a smoother finish.
When the draw is done, the resulting tube must be expanded for further processing. Usually, the smallest diameter is the final size of the tube. In this process, the tube is rotated while passing through cross rolls to generate radial stresses and expand it. The optimum die angle for this process varies by material and diameter-to-thickness ratio. Generally, high-angle dies thin the tube wall, while low-angle dies thicken it.
Manufacturer of standard and custom machinery for cold working welded and seamless carbon steel, bearing and low alloy steel, stainless steel, copper and aluminum and nonferrous metals. Products include cold drawing, hot and warm rolling, slitting, winding, drawing, bar drawing, strand casting, cutting, and spraying machines. Custom design, fabrication and repair services available for new and existing equipment.
During cold drawing, the metal is riveted and its strength properties (tensile and yield strengths) increase simultaneously with its plasticity decreasing. The dependences on which these indicators change are specific for each alloy and depend on technological parameters of the drawing process, namely: drawing speed, drawing route, and the half-angle of the drawing die.
The energy-power parameters of the drawing process can be estimated experimentally by measuring strain gauges during the drawing operation, or by using well-proven mathematical models in such software packages as QForm, ABAQUS, and DEFORM. However, in order to build an accurate model of the drawing process that reflects the influence of hardening and drawing variables on the changing characteristics of the drawn metal, it is necessary to conduct tensile tests on samples of the material under study and develop equations for the dependences on which they change in cold work. This requires additional time, money and effort. However, the results are worth it. The more data on which to base a model, the more accurate it will be. The more accurate the model, the better the energy-power parameters that can be predicted. This will allow for more efficient use of the equipment and thus less waste of resources. Moreover, it will also make possible the production of better quality materials. This, in turn, will help to reduce costs for manufacturing products that require these materials.