Fig. 1511.
Thus in [Fig. 1511] the work w has such a projection and a parallel piece p is inserted to take the jaw pressure. By placing the broadest work surface g against the fixed jaw the work will be held true whether the movable jaw springs or not, because there will be surface g and surface h guiding it.
Fig. 1512.
But if the work were reversed, as in [Fig. 1512], with the broadest surface against k, then if k sprung in the direction of c, the work would not be shaped true.
