Fig. 1666.
[Fig. 1664] represents a tool holder in which two tools may be held as shown, or a single tool right-hand or left-hand as may be required, or the tool may be held at the end of the holder as in [Fig. 1665]. The advantage of such a holder is well illustrated in the case of cutting out a T-shaped groove, because with such a holder a straight tool can be used for the first cuts, its position being shown in [Fig. 1665], whereas in the absence of such a holder a tool bent as in [Fig. 1666] would require to be used, this bend giving extra trouble in the forging, rendering the tool unfit for ordinary plain work, and being unable to carry so heavy a cut or to cut so smooth as the straight tool in [Fig. 1665]. In cutting out the widest part of such a groove the advantage of the holder is still greater, because by its use a tool with one bend, as in [Fig. 1667], will serve, whereas without a holder the tool must have two bends, as shown in the figure, and would be able to carry a very light cut, while liable to dig into the work and break off.
Fig. 1667.
Fig. 1668.