Abstract: Apparatus and method for duplicative notching of the serration edge on a key blank according to the serration edge of an existing key serving as a templet. An axially movable key edge notching punch is controlled by the templet for punching a notch in the serration edge of the key blank corresponding to a notch in the serration edge of the templet when the punch is driven toward the key blank. The key blank and the templet key may be supported in a cassette which is indexible relative to the punch. The cassette and the notching mechanism are especially advantageous for notching the serration edges of key blanks carried by wallet size plastic cards.