Natural diamond wire drawing die is made of high-quality natural diamond, which has the advantages of strong wear resistance, high smoothness and long service life. It is an indispensable tool for wire, cable and various wire drawing manufacturers. Artificial diamond wire drawing die is made of high-strength synthetic diamond polycrystalline core material, which has high hardness, good thermal conductivity, strong wear resistance, long service life It is suitable for drawing all kinds of metal wires.

Compared with foreign products, domestic drawing die blank has the following obvious shortcomings

① The entrance angle is small. In the process of drawing, the wire first contacts with the entrance area of the die core, and the cone angle of the entrance area is small, which not only increases the contact area between the wire and the inner hole, increases the friction, but also hinders the introduction of lubricant, which makes the lubrication effect worse in the process of drawing, and seriously affects the service life of the die.

The entrance angle of foreign wire drawing die products increases, which effectively avoids the scratch between wire rod and wire drawing die, and brings in more lubricant, enhances the lubrication effect and reduces the wear of die core. This change improves the surface quality of wire rod and the service life of drawing die.

② The working area is short. Compared with domestic drawing dies of the same specifications, the working area length of foreign drawing dies is generally much longer. The longer working area is conducive to the reduction and uniform distribution of friction force in wire drawing process, reducing the wear of inner hole of wire drawing die and improving the service life of die. The long and narrow working area can reduce the gap between wire rod and drawing die, and force more lubricant into the middle of wire rod and inner hole under high pressure, resulting in better lubrication pressure. The temperature of the wire out of the inner hole is lower, the drawing force is reduced, and the metal flow is more uniform in the drawing process, which is conducive to the improvement of the drawing speed and the surface quality of the wire. In addition, this type of work area design prevents the lubricant from escaping from the inlet end of the drawing die.

In China, due to the short working area, the effective use area in the hole is small, which not only increases the friction and wear, but also wastes raw materials and increases the cost.

③ The sizing area is not obvious. Sizing area is the last link to determine the final size of wire rod. The short and uneven sizing area will directly affect the final quality of wire rod. The short sizing belt is easy to cause the product size out of tolerance and make the drawing die wear and scrap quickly. The obvious and straight sizing area can produce high precision and high surface quality wire rod, and is conducive to reducing wear and greatly improving the service life of wire drawing die.

According to the comparison of wear curves of wire drawing dies made in Germany and those made in Xiangtan Iron and Steel Co., Ltd., the two kinds of wire drawing dies work under the same drawing conditions: workpiece material: 65 steel wire rod; drawing speed: 3.64m/s; drawing lubricant: soap powder; surface coating before drawing: sulfuric acid pickling, phosphating, borax coating. The test results show that the structure of the drawing die has a great influence on the use of the drawing die. The service life of wire drawing die made in Germany is 2.72 times longer than that of wire drawing die made in Xiangtan Steel. The above comparative analysis shows that the wear rate of the drawing die can be reduced and the service life of the drawing die can be prolonged by optimizing the inner hole of the drawing die. Therefore, it is of great significance to optimize the drawing die and improve the production efficiency of wire rod in China.