In using this tool for cutting a groove it is better (if it be a deep groove, and imperative if it be a broad one, especially if the work be slight and apt to spring) to use a grooving tool narrower in width than the groove it is to cut, the process being shown in [Fig. 1293], in which w represents a piece of work requiring the two grooves at a and b cut in it. For a narrow groove as a the tool is made about half as wide as the groove, and a cut is taken first on one side as at c, and then on the other as at d. For a wider groove three or more cuts may be made, as at e, f, g. In all cases the tool while sinking the groove is allowed to cut on the end face only; but when the groove is cut to depth, the side edges of the tool may be used to finish the sides of the groove, but the side and end edge must not cut simultaneously, or the tool will be liable to rip into the work.
Fig. 1294.
Hand Tools for Brass Work.—In addition to the graver as a roughing-out tool for brass work, we have the tool shown in [Fig. 1294], the cutting edge being at the rounded end a. It is held firmly to the rest, which is not placed close to the work (as in the case of other tools), so as to give the tool a wide range of movement, and hence permit of the cut being carried farther along without moving its position on the rest. It may be used upon either internal or external work.
For finishing brass work, tools termed scrapers are employed.
Fig. 1295.
[Fig. 1295] represents a flat scraper, the two end edges a and the side edges along the bevel forming the cutting edges.