The most common and essential tool in stamping factories is the punch press, which has a set of molds on each press to process various shapes of stamped products. Due to the need to calculate the tonnage of the molds, it is necessary to confirm the size of the punch press. Before planning each set of molds, priority should be given to calculating the tonnage to avoid incomplete punching due to insufficient tonnage.

The tonnage of the punch press is mainly related to the force required for stamping. Punching has punching force, and pulling also has pulling force. If the tonnage is not sufficient, the pulling will not be in place.

When selecting punching machines, stamping processing plants should add up the punching force, unloading force, bending force, and top rod force of the entire set of molds, multiply by a safety factor of 1.3, and the selected punching machine tonnage should be greater than or equal to this result to ensure rationality. Let's take a look at a formula below: F=LT σ bf

1. L refers to the length of the cutting edge line. For example, if a square hole is punched, its cutting edge line length is the sum of the lengths of the four sides of the square hole, which is exactly its circumference;

2. T refers to the thickness of the material, which is the same as above in millimeters, and f is the punching coefficient, usually taken as 1.3;

3. σ b refers to the tensile strength of the stamped steel plate material.

The result obtained by multiplying the above several factors in a stamping factory is the punching force, but the unit is in newtons. To convert it to tons, divide by 9800 to obtain the basic tonnage. Then, considering the safety margin of punching and the force required for unloading, pushing, and other operations, divide this tonnage by a coefficient of 0.7 to obtain the tonnage of the machine tool.

This article is from EMAR Mold Co., Ltd. For more EMAR related information, please click on www.sjt-ic.com,