DMT Dia-Flat Diamond Lapping Plate for Flattening Conventional and Waterstone, 4 by 10 Inch

I was researching some new stones and noticed I hadn't reviewed this yet. I bought it in June of 2014 and it is now September of 2024 as I write this review -- ten years, wow! I am a casual hobby wood worker, and still using it to flatten my water stones of grits and stones from Norton 220, Shapton glass 220, to 1000 and 8000 grit Ohishi. I will hazard a wild guess that it has been actually lapping those stones flat for a total of about 30 hours over ten years (3 hours per year would be 15 minutes flattening per month, which seems about right for my usage). I paid 180 for it then, so if we say 30 hours, then that is 6 dollars per hour of use. It still works as well as it did after the first year, as far as I can recall, so I see no reason it won't work for another 30 hours and another decade. I do not see any visible rust on it, and I don't use any special measures to avoid rust, just regular RO (reverse osmosis) water out of the tap. I do towel it off after a sharpening session to dry it off a bit, but I don't fuss. Yes it was a little pricey, but I feel like I got what I paid for.

I can't say enough about this new DIA-FLAT from DMT.Having previously used an XXCoarse DIA-SHARP (D8XX) to flatten my Norton waterstones, the DIA-FLAT has taken an already decent product and improved it on several fronts.SIZE: This massive 10" by 4" plate is much bigger than the various sharpening stones on the market (and much bigger than my D8XX that is only 8" by 3"). This allows you to move your sharpening stone around without ever leaving the edges of the DIA-FLAT.WEIGHT: The biggest surprise is the weight of the DIA-FLAT, at 4 pounds it is 50% heavier than the 2.7 pound D8XX.SURFACE: The DIA-FLAT shares the D8XX's coarseness of 120 microns, but instead of being clumped in a series of small circles -- the entire services is coated with 30 carats of diamonds (3/4 carat per square inch!) with a guaranteed flatness within 0.0005".BOTTOM LINE: The DMT DIA-FLAT makes it simpler than ever to achieve and maintain a truly flat sharpening stone, assuring a better sharpening experience -- and more importantly, a better experience using your sharpened tools and/or utensils.ONE TIP FOR USE: If you are someone who uses several sharpening stones (coarse to fine) to achieve a polished, even edge -- make sure to run your DIA-FLAT under running water and thoroughly rinse off the particles from one stone before moving to the next, so as to prevent cross contamination. This is difficult to do, but it is a necessity if flattening more than one stone.

Was NOT too impressed with the reviews so before I gave this diamond lapping plate a chance I opted to get the "Maxi-smart Lapping Plate 2.0." Quality control was its downfall in my opinion. It was NOT flat at all and was convexing my Ohishi waterstones. So, I returned it quick faster than a hurry! I was hesitant to buy DIA-FLAT LAPPING PLATE because of how expensive it was for my budget and for the reviews as well, but I like to trip on the same lapping stone...Anyway, I got my DIA-FLAT LAPPING PLATE and it was FLAT! Just like EARTH! Kidding! But seriously this plate is true to its dead flatness and so far so good. Now, the next thing, will it stand the test of time? Will the diamonds embedded in the plate remain in there location after multiple uses. Time will tell but for right now, I am very pleased with the lapping plate!

I've owned the Dia-Flat for a few months, and can say without reservation that it flattens waterstones flawlessly, and can even be used to lap smaller tools. Previously, I used sandpaper, drywall mesh, and other diamond plates for flattening; each of these methods had drawbacks. Sandpaper wears unevenly, and can be tricky to use without unevenly abrading whatever surface you're working as well. Flattening water and oil stones brought about the early demise of a couple of my regular DMT diamond plates. The most sensible explanation I've encountered for this is that the loose particles from the stone can wear away the regular diamond plate's nickel coating. This doesn't happen with the Dia-Flat. The only drawback to the Dia-Flat is its price, but in this case as in so many others you get what you pay for.I place the Dia-Flat on a stand made by DMT in my kitchen sink and flatten stones on it under running water. Rinse any remaining grit from the Dia-Flat between stones. One tip for flattening polishing stones is to back off your pressure after the stone is flat, and lightly abrade the surface of the stone before use. DMT includes this tip in the instructions, and it works.

I was looking for a convenient way to maintain my waterstones. This product got favorable comments from respected reviewers. My main concern is durability of the product. Other products from this maker have been somewhat short-lived. The coating is said to protect the abrasive from degradation. We shall see. This plate leaves water stones with a scratched surface. I hope that will diminish with some further use. It does flatten stones quickly.

This product is not cheap but it does a good job flating cuped stones.

I purchased this as my other lapping plate is too fine for waterstones under 500 grit. My Shapton Kuromaku 320 was made unusable as it got too smooth. I had some extra change lately so I wanted to try this very expensive one out. The surface is LOADED with grit contamination. It mangled the water stone with heavy deep scratches all over it.Not only that, but there's big gaps and not many diamonds with the electroplating. It's obscene at a stone this expensiveMy stone from a competitor is HALF the price, much better and higher quality diamonds and electroplating, NO grit contamination, plus a rubber underside. Don't waste your money on this. This American company definitely had quality control issues to work out