DMT DiaSharp diamond sharpening plates
By Abhijit Menon-Sen <email@example.com>
A friend sent me a pair of
“bench stones”. These are steel plates surfaced with diamond
particles—an alternative to old-fashioned oilstones for sharpening steel
cutting edges. I have been using them for several months now, and they
have lived up to their reputation as being fast, durable, and
convenient. I am very happy with them.
I have the D6CX and D6EF, each of which has two continuous sharpening
surfaces measuring 150mm*50mm (6"*2"). The D6CX has extra-coarse (220
grit) and coarse (325 grit) sides, while the D6EF has fine (600) and
extra-fine (1200) sides.
I have used them to sharpen kitchen knives, sharpen and flatten the back
of a very hard plane iron, restore the badly-damaged cutting edges of
some old chisels that belonged to my grandfather, and hone some new
Narex chisels and other assorted tools.
I follow more or less the same process shown in this
by Paul Sellers.
The DMT plates are fast and a pleasure to work with. Flattening large
steel surfaces does take a half-hour or so of extra-coarse rubbing (mind
your knuckles don't scrape the plate! I learned this the hard way), but
that isn't a task I would even attempt on my old Norton oilstone. Tuning
up a blunted (not damaged) edge takes a couple of minutes at most, while
restoring a nicked edge might take ten.
I use the plates with a bit of water sprayed from an old bottle of glass
cleaner, and wipe them down afterwards with an old shirt. They are easy
to maintain (but the coarse grits must be cleaned gently, because they
will happily shred cloth), and do not need to be flattened periodically
the way an oilstone might. The fine surface developed a few tiny black
spots on the very first use, but extensive use thereafter has not made
them any larger or more numerous. (DMT is reputed to have good customer
support, but they didn't respond to my question about the black spots.)
(I also have the
stand. The rubber feet do keep it from moving, and the clearance makes
it easy to flip the plates over. It works fine, but I could easily do
I like sharpening things, but I am not obsessive about it. I have not
tried to measure how flat the surface actually is, nor have I looked at
the sharpened edges under a microscope. The plates are flat enough, and
the edges sharp enough for me; and it doesn't take too long to get them
DMT manufactures a great variety of these plates: larger and smaller
sizes, coarser and finer grits, single- and double-sided, or with
“interrupted” surfaces that reduce the buildup of swarf (abraded steel
particles that must be cleaned away). I might try a single-sided 8"*3"
continuous surface plate someday—it should make it a little easier to
sharpen my larger knives.