the point and the cutting edge is set
almost square, as at _C_, Fig. 7, a smooth finish can be obtained; the
cut, however, should be light and the outward feed uniform. The work is
next reversed in the centers and the driving dog is placed on the end
just finished; the other end is then faced, enough metal being removed
to make the piece 14-1/2 inches long, as required in this particular
case. This completes the facing operation. If the end of the work does
not need to be perfectly square, the facing operation can be performed
by setting the tool in a right-angled position and then feeding it
sidewise, thus removing a chip equal to the width of one side. Evidently
this method is confined to comparatively small diameters and the
squareness of the turned end will be determined by the position of the
tool's cutting edge.
=Turning Tool--Turning Work Cylindrical.=--The tool used to turn the
body to the required diameter is shaped differently from the side-tool,
the cutting edge _E_ of most tools used for plain cylindrical turning
being curved as shown in Fig. 8. A tool of this shape can be used for a
variety of cylindrical turning operations. As most of the work is done
by that part of the edge marked by arrow _a_, the top of the tool is
ground to slope back from this part to give it keenness. The end _F_, or
the flank, is also ground to an angle to provide clearance for the
cutting edge. If the tool did not have this clearance, the flank would
rub against the work and prevent the cutting edge from entering the
metal. This type of tool is placed about square with the work, for
turning, and with the cutting end a little above the center.
[Illustration: Fig. 8. Tool used for Cylindrical Turning]
Before beginning to turn, a pair of outside calipers or a micrometer
should be set to 2-1/4 inches, which, in this case, is the finished
diameter of the work. Calipers are sometimes set by using a graduated
scale as at _A_, Fig. 9, or they can be adjusted to fit a standard
cylindrical gage of the required size as at _B_. Very often fixed
caliper gages _C_ are used instead of the adjustable spring calipers.
These fixed gages, sometimes called "snap" gages, are accurately made to
different sizes, and they are particularly useful when a number of
pieces have to be turned to exactly the same size.
The turning tool is started at the right-hand end of the work and the
tool should be adjusted with the left hand when beginning a cut, a
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