may have an
adjusting screw as at _C_; for special work, different forms or shapes
are also required. The stop gages on some machines, instead of being
held in the turret, are attached to a swinging arm or bracket that is
fastened to the turret slide and is swung up in line with the spindle
when the stock is fed forward.

The center drilling tool _D_ is designed to hold a standard combination
center drill and reamer. This type of tool is often used when turning
parts that must be finished afterwards by grinding, to form a center for
the grinding machine. The adjustable turning tool _E_ is used for
turning the outside of gear blanks, pulley hubs or the rims of small
pulleys. The pilot _a_ enters the finished bore to steady the tool, and
cutter _b_ is adjusted to turn to the required diameter.

[Illustration: Fig. 15. Various Types of Tools for the Turret Lathe]

The cutting-off tool-holder _F_ (which is held on the cross-slide of the
turret lathe) is usually more convenient than a regular toolpost, as the
blade can be set closer to the chuck. The blade is held in an inclined
position, as shown, to provide rake for the cutting edge; the inclined
blade can also be adjusted vertically, a limited amount, by moving it in
or out. The multiple cutting-off tool _G_ holds two or more blades and
is used for cutting off several washers, collars, etc., simultaneously.
By changing the distance pieces between the cutters, the latter are
spaced for work of different widths. The flat drill holder _H_ is used
for drilling short holes, and also to form a true "spot" or starting
point for other drills.

Knurling tools are shown at _I_ and _J_. The former is intended for
knurling short lengths and is sometimes clamped on top of the cut-off
tool on the cross-slide, the end being swung back after knurling (as
shown by the dotted lines) to prevent interference with the work when
the cutting-off tool is in operation. The knurling tool _J_ has a shank
and is held in the turret. The two knurls are on opposite sides of the
work so that the pressure of knurling is equalized. By adjusting the
arms which hold the knurls, the tool can be set for different diameters.

Three styles of drill holders are shown at _K_, _L_ and _M_. Holder _K_
is provided with a split collet (seen to the left) which is tightened on
the drill shank by a set-screw in the holder. This holder requires a
separate collet for each size drill. The taper shank drill holder _L_