Punching is a forming process that uses a punch press to force a tool, called a punch, through the workpiece to create a hole via shearing. Punching is applicable to a wide variety of materials that come in sheet form, including sheet metal, paper, vulcanized fiber and some forms of a plastic sheet. The punch often passes through the work into a die. A scrap slug from the hole is deposited into the die in the process. Depending on the material being punched this slug may be recycled and reused or discarded. Punch tooling (punch and die) is often made of hardened steel or tungsten carbide.
Very often the finished product requires various types of holes, differing by position and shape. The possibility of making these holes inside the roll forming line makes it possible to obtain the product without the need for additional processing steps, with better quality and reduced cycle time and semi-processed products warehouse. The workpiece is often in the form of a sheet or roll. Materials for the workpiece can vary, commonly being metals and plastics. The punch and die themselves can have a variety of shapes to create an array of different shaped holes in the workpiece. Multiple punches may be used together to create a part in one step.
It has many advantages:
The dimensional accuracy is guaranteed by the mold, so the processed parts have stable quality and good consistency, and have the characteristics of “ exactly the same”.
Stamping can obtain parts that are thin, light in weight, good in rigidity, high in surface quality, and complex in shape that cannot be manufactured by other processing methods;
High material utilization rate, which is less and no chip processing;
High efficiency, convenient operation, and the required technical level of workers is not high;
The mold has a long service life and low production cost.