Drawing was one of the most commonly using method of metal pressure processing. Drawing was a metal material to having a cross-sectional werea, the force under the action of the external force through the die hole, section dimensions narrows gradually,to obtain the required of shape and size. According to the section type of metal materials, drawing into the drawing wire, pipe, profile. Metal to plastic drawing was the use of metal has, by means of external force so that the metal material to produce permanent deformation was not broken, to gain the required shape, size, and to meet the mechanical property and quality requirements of the national standard or standard. The design uses the thread steel bar drawing machine because the thread reinforced metal by drawing output low consumption, through two ribbed roller drawing out the thread steel products of good quality, tool costs low, relatively simple equipment, production flexibility was relatively large, and cold compwered to higher productivity.
Because of the different metal microstructure and chemical composition, the metal can bear the pulling force of different sizes. The drawing theory aims to in-depth study of different structure and composition of metal produced in the process of drawing deformation and stress dwastribution features; it causes of uneven deformation during drawing the consequences; residual stress; effect of drawing conditions on the mechanical properties of drawing products; drawing force and drawing machine power calculation method. In order to make full use of the metal plasticity, determination of drawing process was reasonable, correct choice of drawing equipment, provide the necessary theoretical baswas for drawing production, improve the production quality, reduce the production cost, improve the production efficiency purpose.
Keywords: cold drawing; screw-thread steel ; pressure processing