Reamers

[GABRIEL ZWIERSKI]

Hello all,
      When you drill a hole in any material using a drill bit, the diameter of
the hole is not uniform over the length of the hole due to many causes (stresses
and variable densities in the material, heatup of the drill bit, material
heatup, etc,).  The purpose of a reamer is to make the hole uniform in diameter
along its length.
      Analogy:You use a cabinet scraper to remove handplane marks, the reamer
does the same thing for holes
      I was taught that a reamer is a HAND tool.  Using it in a drill or drill
press defeats the purpose (the reamer gets hot and expands (i.e. variable
diameter holes).  The square ending on the non-business end usually indicates
"please insert me in tap handle and use me manually".  Of course, the reamer has
to be slightly bigger than the hole in order to do its job, but what the hey!
Undersize the hole.
      Spoon reamers (the cheapest) sort of work OK, but fluted reamers work
better, the best (and most expensive) being spiral fluted.  These are available
from machine supply houses in both fractional, decimal and metric sizes (I
don'tremember seeing any in letter or number, but I could be wrong).
      IMHO It would seem to me, as a non-RPT (I'm a finish and case repair
specialist), you would pull the old pin and then use the reamer (by hand) to
true up the hole  for the next size (or so) pin.

            Gabriel Zwierski