Below is my transcription of the instructions which came with an old set of
expansion reamers. - Grant Erwin, August 2005
 
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                          CRITCHLEY TYPE REAMERS
Size       Range of Expansion       Length of Blades       Length Over All
  A         15/32" to  17/32"        2"                       5 1/4"
  B         17/32" to  19/32"        2"                       5 3/4"
  C         19/32" to  21/32"        2 1/4"                   6 1/4"
  D         21/32" to  23/32"        2 1/4"                   6 3/4"
  E         23/32" to  25/32"        2 1/2"                   7 1/4"
  F         25/32" to  27/32"        2 1/2"                   7 3/4"
  G         27/32" to  15/16"        3"                       8 1/4"
  H         15/16" to 1 1/16"        3"                       8 3/4"
  I        1 1/16" to 1 3/16"        3 1/2"                   10"
As indicated, each reamer expands to the smallest size of the next larger
reamer, thereby eliminating many odd sizes which would otherwise be necessary.
 
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                            CARE OF THE REAMER
                            
When adjusting the reamer, care should be taken to see that the nuts are not
drawn too tightly, just firmly against the collars.

The nuts should never be given more than one full turn for each cut, but
should be turned sufficiently to make it cut. If it doesn't cut it will
burnish the surface of the hole and dull the reamer.

In sharpening the reamer the clearance should be kept about the same. The
landing or circular ground edge along the front of the blades should be about
one-hundredth to one sixty-fourth of an inch wide.

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                               INSTRUCTIONS

Best results can be obtained by taking shallow cuts, testing after each cut
with the pin to be fitted.

If two or more holes are to be reamed to the same size, as for piston pins or
king pin bushings, best results will be obtained if all holes are reamed after
each expansion of the reamer. Then expand the reamer for another light cut and
follow through all the holes again. Continue this until the desired size is
reached. When the final cut is taken all the holes should be uniform in size.

In reaming cast iron, bronze or brass there should not be any oil used, the
dryer the surface, the nearer perfect bearing and perfectly round hole is
obtained. In using oil the reamer will cut the smoothest looking hole, but
will give you from 25 to 40% less bearing.

In reaming steel it is very important to use a good thread or screw cutting
oil.

Aluminum is about the most difficult metal to ream, and it is practically
impossible to ream it dry. About the best results can be obtained by the free
use of kerosene.

The work should be held stationary in a vise and the reamer turned with a
double end wrench, such as a tap wrench or any kind of wrench that will give
equal leverage on two sides. It is just as nearly impossible to ream a good
hole by driving a reamer with a single end wrench as it is to drive a tap with
a single end wrench. If the reamer is held in a vise and the work turned over
the reamer by hand it will very often cut the hole rough and too large on the
end the reamer is started from, and sometimes larger on both ends, especially
on work where the hole is not exactly in the center, which throws more weight
on one side of the reamer than the other. For instance a connecting rod, it is
practically impossible to hold such a piece so that the weight against the
reamer will be the same on both sides. The heavy end will be lifted either too
high or not high enough.