According to jdturner :
On Apr 12, 7:57 pm, "Brent" wrote:

the problem with SHARPNESS is it is not a good measure of the
effectiveness of a cutting tool....

[ ... ]

Anyway, I thought this info tidbit might be of some interest.

Once upon a time (25 years ago)...

[ ... ]

The microtome consisted of an 8-10 inch knife fixed in position at an
angle of roughly 30 degrees from the verticle, and a mounted block of
tissue (about 1 in sq.) which passed over the knife, one rotation at a
time, producing this thin tissue slice similar to a peeling cut in
woodturning.

The knife was of a fine grained steel... (sorry but I didn't know
anything about steel at the time) and shaped like a wedge, about 30
degrees and 1 1/2 inches deep (8-10 inches long).

The ones which I have can easily be described as being like
straight razor blades on steroids. :-)

The edge was
sharpened on a super flat, ectched, thick glass plate using some
watery toothpaste-like slurry. The blade was held at an angle and
passed over the plate in a figure eight pattern, then flipped over to
sharpen the other side. The passes were made mechanically and were
counted and timed. (Keeping the angles even) Each knife had its own
glass plate. Eventually, the glass plates were sent out for
resurfacing; i.e. etchnig and flattening.

Aha! This is useful information -- and probably explains the
handles which came with the blades -- for sharpening -- not for the
cutting of the slices. (I've owned a bladeless microtome for decades,
and only fairly recently did I get some blades for it from an eBay
auction.) I'll eventually need to sharpen those blades.

Enjoy,
DoN.
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