Blanking: The blanking is the operation of cutting of flat sheet to the desired shape. The piece detached from strip is known a blank. The metal punched out is the required product and the plate with the hole left on the die goes as waste. While blanking the size of the blank is governed by the size of the die and the clearance is left on the punch. Blanking is always performed as the first operation
Piercing: The piercing is the operation of production of hole in a sheet metal by the punch and the die. The materials punched out to form the hole constitute the waste. The punch point diameter in the case of piercing is less than or equal to the work material thickness. The punch governs the size of the hole and clearance is provided on the die. Fig. shows punch and die set for piercing.