PunchingShaped dies are used to pierce tubing or flat stock to create a hole of a specific size or shape, or a component from flat stock. Punching can be performed on various metals (from stainless steel to brass), and is cost effective and suitable for medium- and high-volume applications. The thickness of the material to be punched determines the size and tolerance of punch. Circle punches are most common, but since MicroGroup machines dies in-house, punches of other shapes are available.