Centre Punch is the commonest of all punches and is a steel rod 90 – 150 mm long and 8 – 13 mm in diameter. It is used to make marls at the centers of holes which are to be drilled and to make marks on a line through which a metal is to be cut. Hence the name center-punch. A light blow with a hammer will be enough to make a mark. Below is the drawing of a center punch.