A cut of 1⁄8 inch deep, that is, reducing the work diameter 1⁄4 inch, may readily be taken with this tool, which, however, requires skilful handling to prevent it from digging into the work.
The shorter the distance from the face e to the heel f the more easily the tool can be controlled; hence, as f serves simply as a sharp and gripping fulcrum it need not project much from the body of the steel; indeed, in many cases it is omitted altogether, the bottom of the steel bar being slightly hollowed out instead. No oil or water is required with the heel tool.
The hand rest should be so adjusted for height that the cutting edge of the tool stands slightly above the horizontal level of the work, a rule which obtains with all hand tools used upon wrought iron and steel.
Fig. 1285.
The graver is the most useful of all hand turning tools, since it is applicable to all metals, and for finishing as well as roughing out the work. It is formed by a square piece of steel whose end is ground at an angle, as shown in the top and the bottom view, [Fig. 1285], a a being the cutting edges, c c the points, and d d the heels.
Fig. 1286.