A method of manufacturing a hole in a component consisting of a composite material, such as a fiber or fabric reinforced plastic part, wherein the component, having first and second oppositely disposed sides, is placed with its first side on a support having an iris diaphragm. A tip which diverges in the axial direction is pressed from the second side of the component through the component, which optionally has a pre-piercing, for formation of the hole or for enlargement of the pre-piercing. The iris diaphragm has a smaller starting opening which receives a narrower region of the tip and opens into a larger opening with increasing penetration of the component by the tip, the component is supported during hole formation over an as large as possible area from the first side. A piercing aid in the form of an iris diaphragm or a die button is likewise claimed.