- Main
- Dia vs. Duo vs. DuoPlus
- Grit Comparison
Dia-Sharp stones have an exceptionally dense, and evenly distributed coating of micronized-monocrystaline diamonds, resin bonded to a nickel-coated solid-steel plate. DMT precision grinds the steel to within +/- .001 flatness so you can flatten plane irons, and chisels with confidence. The diamond surface is quick cutting and durable, even under heavy use. At first the stones have a very aggressive feel. This will smooth out after a few sharpenings without impacting performance.
One of the great things about DMT stones is that they can be used dry. That’s a huge benefit when working away from a sink, or on a wooden workbench. For dry clean up use a polymer eraser. If you prefer wet sharpening, use a splash of water and wipe your stone clean at the end of your sharpening session. Oil is also an option – with the proviso that the stone isn’t stored in kerosene.
All DMT products are designed for a long service life. Store stones dry, (a simple wipe with a towel is fine) and leaf between stones with towel, cloth, paper, or plastic storage sleeves to prevent abrasive sides from rubbing.
We carry a full range of sizes and grits in the Dia-Sharp Stones so you can match the stone to the tool:
With 5 carats of industrial diamond the 10″ by 4″ stones have a luxuriously large surface for flattening chisel and plane backs, or truing up the sole of a plane. The width is perfect for use with sharpening jigs. They’re also a great size for flattening other stones. 67% more surface area than 8″ stones.
8″ by 3″ stones are are good all around, and give a nice long stroke at a slightly lower price point that the 10 inchers. DMT manufactures this size in the widest range of grits.
For carving tools, pocket knives, or sharpening on the go we stock 6″ by 2″ and 4″ by 7/8″ stones. They both fit easily into a tool kit, and the 4″ stones fit perfectly in your Chisel or Carving Rolls.
All stones are single sided. No-Skid Mat available separately.
DMT Dia-Sharp stones are Made in the USA
Which Grit Diamond Stones for Sharpening?
- When you own a grinder – We recommend using the fine and extra fine grits for developing a wire edge. for edge repair we use a grinder. for final polish we use an 8000 grit water stone.
- When you don’t own a grinder – In addition to the stones above we think extra coarse and coarse stones are excellent for removed damage on an edge.
Which Size Diamond Stones for Sharpening?
- For the Shop
– 8″ stones are a very nice size with a good length of sharpening stroke. - For the Road – 6″ stones are small enough for travel, but still are long enough to do real work.
- On a Budget – We would not compromise on grit but try for at least 6″ stones.
- The Sky is the Limit – 10″ stones are overkill. But my are they nice!
DiaSharp stones have a solid un-interrupted diamond surface on one side of a solid steel backing. They can sharpen pointy and narrow tools, as well as wide irons and chisels. Solid steel construction makes these the heaviest DMT stones, and also the flattest. The extra heft keeps them firmly in place on a non-stick mat, but doesn’t travel well – with the exception of the DiaSharp Credit Card sharpeners which fit in a wallet.
Duosharp Stones are the classic patented DMT Polka-Dot Sharpening stones. Stones are two sided, and have an interrupted steel surface on both sides. The recessed dots keep abraded metal dust off the abrasive surface of the diamonds, for very fast sharpening. The dots will catch tools much smaller than 1/4″ or anything with a curved surface like a gouge – but their compact construction, light weight, and two-grit configuration make them an excellent choice for many users.
DuoSharp Plus stones add a 3/4″ wide uninterrupted surface to the ends of what would otherwise be a classic 8″ DuoSharp bench stone. The uninterrupted surface is for sharpening pointy, or narrow tools. Like the regular DuoSharp, these stones are light weight, and travel well. If you regularly sharpen chisels, knives and plane irons, but only occasionally need to sharpen tools narrower than 1/4″ the DuoSharp is good option.
Use for Edge Repair, resetting or changing a bevel angle, or flattening another stone.
Extra Coarse – Diamond Size: 60 micron, 220 mesh DMT Color Code: Black
Use for edge repair, resetting or changing a bevel, or flattening fine grit water stones. Good first step for flattening the backs of chisels and plane irons. Color code: Black 60 micron, 220 mesh.
Coarse– Diamond Size: 45 micron, 325 mesh DMT Color Code: Blue
Use for restoring very dull edges, coarse cutting tools, such as froes, lawnmower blades, axes or mortise chisels. Can be used for flattening chisels and plane irons.
Fine– Diamond Size: 25 micron, 600 mesh DMT Color Code: Red
Good intermediate step for plane irons, chisels, or carving tools. Perfect for general sharpening – this is the grit we keep in the kitchen to sharpen knives that see abuse. For woodworking we recommend following this grit with a finer grit diamond stone, water stone, or diamond paste.
Extra Fine – Diamond Size: 9 micron, 1200 mesh DMT Color Code: Gray
Good for use as an intermediate step for plane irons, chisels, or carving tools. Excellent single stone for sharpening kitchen knives. For woodworking we recommend following this grit with a water stone, diamond paste, or extra extra fine grit stone.
Medium Extra Fine – Diamond Size: 6 micron, 4000 mesh
Produced by DMT on a limited basis and intended as in intermediate step between the Extra Fine and Extra Extra Fine stones.
Extra Extra Fine– Diamond Size: 3 micron, 8000 mesh DMT Color Code: Tan
Provides the finest grade micronized bonded diamond abrasive available. Surprisingly quick stock removal with millions of diamond cutting edges.



























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