During the stamping production, the punch drives the die to move back and forth, which determines that the processing accuracy of the stamping products is mainly affected by the following three aspects, namely, the size and accuracy of the die, the accuracy of the die fitting, and the accuracy of the punch.

1. Influence of die size and precision on the precision of stamping products

Stamping products will have their own elastic recovery, elastic deformation of the mold and temperature rise caused by deformation during forming. The deviation between the product and the mold size will affect the accuracy of stamping products.

2. Influence of die fitting accuracy on stamping product accuracy

During the work of the punch, the slider and the master die are often installed into the die-set module with guide posts to maintain the centering accuracy. If the solid guide posts are not used, it is difficult to maintain the accuracy, which will lead to improper alignment of the dies and cause the products to be inward, misaligned and bent.

3. The influence of punch's own precision on the precision of stamping products

The body, worktable, sliding block and other structural parts of the punch press and the forging die will all produce changes in elastic deformation. The elastic deformation error between the punch and the die is the accuracy of the bottom dead center position of the punch slider, which can also be called the dynamic accuracy of the punch when the punch is loaded, and determines the forging processing accuracy of the bottom thickness and flange thickness of the stamped product.

The accuracy of a punch is usually expressed by its static accuracy and rigidity. The accuracy grade under static state can be divided into special grade, grade 1, grade 2 and grade 3 according to the static accuracy index of JIS punch in Japan. For the punch, the static grade is a major factor, but the rigidity of the punch is also an important factor that cannot be ignored, which is the strength of the punch.