DMT Dia-Flat Lapping Plate

DMT Dia-Flat Lapping Plate

Price: $244.79 $184.99 (Save 24%)
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  • Utilizes New Diamond Hardcoat Technology
  • Hand Tested Flat to within .0005"
  • Flattens Waterstones with Ease
  • Large 10" x 4" Lapping Plate


The DMT Dia-Flat is a high quality diamond lapping plate that can handle all your water stone flattening needs.

It is a large lapping plate measuring 10" long and 4" wide. The Dia-Flat uses 120 micron (120 mesh) monocrystalline diamond abrasives. If you use water stones, you know that the biggest drawback is the fact that they will wear unevenly and require flattening. It is important to keep water stones flat for best performance, especially when you're sharpening woodworking tools. We have tested the Dia-Flat and found it to be the fastest method of flattening water stones.

Certified Flat

To properly flatten your water stones, your lapping plate must be very flat. All of the DMT Dia-Flat stones are carefully machined to be flat within .0005 inches. DMT takes this one step further and tests EVERY flattening stone to make sure it meets their strict specifications. If it doesn't pass the test, it does not go out. You will receive a Certificate of Flatness stating that your lapping plate has met these rigorous standards. The head of production at DMT handles this process and personally signs off on each unit.

Hardcoat Technology

The Dia-Flat Lapping Plate uses a new DMT proprietary process they call their Hardcoat Technology. DMT has been known for many years for producing long wearing diamond coated products but this is a significant step up in durability even compared with the other stones they manufacture. This is critical to the long term effectiveness of their flattening stone because the flattening process puts a tremendous amount of wear on stones compared with sharpening.

Made in the USA by DMT.

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Lapping Plate Comments

I have used water stones for years and like everyone else, I've had to flatten the stones. But too often the inexpensive silicon carbide flattening stones are just not flat enough to do the job properly. First, they are not machined and therefore don't start out completely flat. Second, they do tend to wear and once they do, they are not useful for flattening.

I was given the opportunity to test the DMT Dia-Flat to see how it would compare to other lapping plates on the market. I was very impressed with the flatness, durability and the speed that it flattens water stones. In speaking with the Technical Director at DMT, he told me that DMT's new Diamond Hardcoat Technology is the reason for the great performance. I was then able to see under magnification the size and shape of the diamonds. Good quality monocrystalline diamond should be uniform in size and very blocky (not pointed which are prone to wear).

John Carmona,
Sharpening Supplies

Video Demonstration of the DMT Dia-Flat Lapping Plate

Q. What is the grit of the diamond surface of the DMT Dia-Flat?

A. It is a 120 micro size. This larger size makes flattening much quicker.

Q. Does DMT have other lapping plates available?

A. There are three DMT lapping plate options. View the comparison chart here.

Need more information?

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