In the process of punching, the metal forming is done via shearing. A hole is created in the work piece using a punch press to force a punch, through the work piece. Often the punch passes into a die through the work. The scrap slug from the hole is deposited into the die. This slug, depending on the material being punched, might be discarded, or recycled and reused. In medium to high production volumes, punching is often the cheapest method for creating holes in sheet metal. Hot punching is another variation of this method, where the work piece is hot at the time of punching.