28.4.1 Filing on a Lathe
When filing work on a lathe, avoid holding
the file stationary against the work. Keep it
moving constantly across the work. If the file is
held in one position, it will “load” with metal
particles and score the work surface.
An ordinary mill file will produce satisfac-
tory results. However, a long-angle lathe file,
Figure 28-16, produces superior results without
chatter. Operate the lathe at a high spindle speed
and use long, even strokes. Release filing pres-
sure on the return stroke.
File safety
As simple as filing may appear, it can be
quite dangerous if a few precautions are not
observed. Keep the following in mind when
filing on a lathe:
Move the carriage out of the way and
remove the tool post.
Use the left-hand method of filing, Figure 28-17.
It involves holding the file handle in the left
hand. The right hand is then clear of the
revolving chuck or faceplate.
Avoid using the right-hand method,
Figure 28-18. This technique places your left
arm over the revolving chuck or faceplate.
Remove all jewelry, (rings, watch, necklaces)
and tightly roll up your sleeves.
Avoid touching the work while it is
revolving.
28.4.2 Polishing on a Lathe
Polishing is an operation used to produce a
fine finish on a piece of work. Like filing,
polishing is not a substitute for a properly set up
lathe and a sharp cutting tool.
454 Modern Metalworking
A
B
Figure 28-15.
Knurling problem. A—Do knurling before turning a
smaller diameter. B—If knurling is done after the
smaller diameter is turned, the workpiece may take a
permanent bend and only a superficial (very light)
pattern will be produced.
Mill file Long-angle lathe file
Figure 28-16.
A standard mill file differs from the long angle lathe file.
Figure 28-17.
The left-hand method of filing is preferred. How
does it differ from the right-hand method shown in
Figure 28-18?