Punching is a metal forming process that uses a punch press to force a tool, called a punch, through the work piece to create a hole via shearing. 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. Punching is often the cheapest method for creating holes in sheet metal in medium to high production volumes. When a specially shaped punch is used to create multiple usable parts from a sheet of material the process is known as blanking. In forging applications the work is often punched while hot, and this is called hot punching.
1，Punching is the most cost effective process of making holes in strip or sheet metal for average to high fabrication.
2，It is able to create multiple shaped holes.
3，Punches and dies are usually fabricated from conventional tool steel or carbides. Create a burnished region roll-over, and die break on sidewall of the resulting hole.