Work Sharp Sharpening System - Manual (Page 11)

Note that the surface of the tool rest and
heat sink (also called the “sharpening
port” in company literature) is also cov-
ered with a pressure sensitive abrasive
(blue arrow) that serves two purposes.
First, when you pull the tool to be sharp-
ened back away from the abrasive on the
underside of the glass plate, the tool rest
abrasive fractures the micro wire edge
that is formed by the sharpening process.
Since you normally push the cutting tool
up against the abrasive on the underside
of the glass plate for a second or two and
then retract it for a second or two, repeat-
ing this process five or ten times per grit,
the wire edge is constantly removed as it
is first formed.
With most sharpening systems the wire
edge is only removed after it is fully
formed which can result in a microscopic
fracture of the very cutting edge you are
trying to establish. By constantly remov-
ing it as it is formed, the quality of the cut-
ting edge is improved.
The second purpose of
this grit face on the heat
sink and tool rest is to
help you position the tool
so it has less tendency to
slide down the incline of
the tool rest and will keep
the cutting bevel nicely in
contact with the abrasive
doing the sharpening.
The heat sink that is built
in as part of the tool rest
directs cooling air to re-
duce heat build up on the cutting edge
which otherwise might burn or damage
the edge.
The strong upper and lower body cast-
ings are held securely in registration, one
with another, by sturdy steel machine
screws (orange arrow). This robust con-
struction is evident throughout the Work
Sharp. It looks to me as if it will last a