Fig. 1009.
Thus, suppose that when new its teeth are of correct height, when the bottom face i, [Fig. 1009], lies upon the rest r, the face h being in line with the centre b b of the work, then as face h is ground the tool must be lifted to adjust its height. On account, however, of the curve of the teeth it is very difficult to find when the chaser is in the exact proper position, which in an ordinary chaser will be when it has just sufficient clearance to enable it to cut, as is explained with reference to cutting up chasers and using them by hand.
Fig. 1010.
Fig. 1011.