There are several common ways of special-shaped wire drawing dies:

(1) The surface shrinkage rate of the special-shaped wire drawing die is too large, resulting in cracks or breakage of the mold. Cracks or fracture marks are overwhelmingly large, and some of them occur due to the release of internal stress. In any material layout, the existence of internal stress is certain, the internal stress that occurs when drawing the wire can enhance the diamond crystallite layout, but when the shrinkage of the drawing surface is too large, can not be smooth in time and then the temperature rise is too high, it will cause the diamond mold to indicate that some materials are removed, and the stress accepted by the microcrystalline layout will be greatly increased, making it easier to crack or break.

(2) the tensile axis of wire rod and the center line of die hole are asymmetrical, resulting in uneven stress effect on wire rod and wire drawing die, and the impact of mechanical vibration can also constitute a high stress peak to wire rod and wire drawing die, both will accelerate the wear of mold.

(3) The uneven hardness of the wire rod and other elements constituted by uneven annealing simply constitute the premature fatigue damage of the diamond drawing die, which constitutes an annular groove and aggravates the wear of the die hole.