Piece A may now be screwed on B and the outside rough turned to within
¹⁄₃₂ of an inch of the finished size.
The ends of the different steps are finished to the proper length with
the tool shown in Fig. 29. This same tool can then be used to turn the
different diameters to within 0.002 or 0.003 of an inch of the required
size. These steps are brought to the final size by filing.
=Filing.=—The file for this work should be less than 1 inch in width.
If it is wider than the steps, a beginner will usually file the portion
at the end of each step smaller in diameter than that which is close to
the square corners.
The different diameters may be measured accurately with the micrometer
calipers.