provided with a straight forming tool and holder mounted on the cut-off
slide. The cutter is backed up by the screws shown, which also provide
adjustment for different tapers within a limited range. The bar is
supported by the three back-rests shown, which also have screw
adjustment.

=Examples of Box-tool Turning.=--Box-tools are not only used for
cylindrical and taper turning on the end of a bar, but for many other
operations. Figs. 9 and 10 show a number of box-tools of different
designs, with examples of the work for which each is intended. While
these tools are designed for some specific part, they can, of course,
with slight modifications be adapted to other work.

[Illustration: Fig. 9. Box-tools and Work for which they are Intended]

A box-tool of the pilot type that is used for finishing, after the
surplus stock has been removed by roughing tools, is shown at _A_, Fig.
9. The work, which is the cone for a ball bearing, is shown at _a_ by
the dotted lines and also by the detail view to the right. The pilot _b_
enters the work before either of the cutters begins to operate on its
respective surface. The inverted cutter _c_, which sizes the flange of
the cone, is held in position by a clamp _d_, which is forced down by a
collar-head screw. The cutter is further secured against a beveled
shoulder at _g_ by the set-screws _f_, and it is adjusted forward by the
screw _e_. By loosening the screws _f_ and the collar-head screw, the
cutter may be removed for sharpening. The cutter _h_ is adjusted to cut
to the proper diameter, by the screws _l_, after which the clamp _k_ is
made level by the screw _j_. The collar-screw _m_ is then used to secure
the tool in place. The cutter is made from drill rod and it is slightly
cupped out on the cutting end to give keenness to the cutting edge. The
adjusting screw _o_, which passes through plate _p_, prevents the cutter
from backing away from the work. This adjusting screw plate has its
screw holes slotted to avoid removing the screws when it becomes
necessary to remove the plate and cutter for sharpening. Pilot _b_ is
held firmly to the tool body by set-screw _r_. The hole _s_ through the
shank makes it easy to remove the pilot, in case this is necessary.

A pilot box-tool for finishing another type of ball bearing cone is
shown at _B_. The shape of the work itself is indicated by the dotted
lines _a_ and by the detail view. This tool is somewhat similar in its
construction to