Diamond Machining Technology (DMT) WM8EF DuoSharp Double-Sided Diamond Sharpening Stone Bench, Fine/Extra Fine, 8 Inch

I had my reservations because I normally use a solid sharpening plate but its become my favourite coarse stone by far. Works smooth, takes a lot of material off and quik while prepping the blade for the higher grit stones. Good stuff!

Have you ever spent a half hour trying to sharpen a knife with a hard blade steel like s30v only to take off barely any material? If so, you know it can be a real pain in the a**. Metallurgists have been doing some crazy stuff with powdered metal alloys in the last 10 years since I started sharpening my own knives. While the old sharpening tech still works, it is painfully slow for these new super hard steels. Something more aggressive is needed. DMT plates provide extremely fast and precise removal of material. Since they are so expensive I was worried about quality because of some reviews, but mine look great. There is a slight break in, but not too long. I was able to reprofile the edge of my benchmade 535 (s30v) in about 10-15 minutes using the extra coarse side. I did not find it to be too coarse like some reviews, and the plates are very flat. I think some reviewers mistake the extremely aggressive removal rate for a more coarse grit. I examined it under magnification and the diamonds appear to be consistently sized and about 220 mesh as DMT says. It is extremely fast even with s30v, to the point that every stroke counts. Instead of mindlessly giving it a few passes and then looking, I found myself concentrating on specific areas of the blade and looking at it after every pass. It allows you to cut so much with each stroke that it is almost like a power tool. DMT says that the extra coarse is a “safe alternative to powered grinding”. This is absolutely true with the added benefit of much less likelihood of heating the blade. It would be very easy to destroy knives as well with this system if it is misused, but that is true with any powerful and useful tool.

I started my sharpening collection about five years ago, and DMT was one of the first brands I bought when buying diamond sharpening stones. The other DMT stones I have worked well and continue to do their jobs. However, the black X-coarse never really cut well from the start, so I mainly used the blue-coarse side. It wasn't until the start of 2021 that I noticed the black x-coarse side was just flaking off if you tried to use it. So this stone was first to get phased out and changed with a new diamond sharpening stone from DMT.

I bought 3 products from DMT, including this stone the DMT Duobase  DMT B8250 DuoSharp DuoBase - bench stone base  and the DMT 10" fine/extra fine  DMT W250EFNB 10" DuoSharp Bench Stone Extra-Fine / Fine No Base . Of the 3, only the 10" exhibited no issues, although the issue with the duobase is minor, one of the feet keeps falling off.But, with the coarse/extra coarse stone, the issue is major and I'm returning it for exchange, hoping to get a good one. The Extra Coarse side doesn't seem to do much of anything at all, barely removing material with significant effort. The Coarse side removes material much faster and easier. Given that I'm trying to flatten the backs of several hard, wide plane blades, I need an extra coarse stone that will actually remove material quickly and easily.The reason for the 3 stars and the exchange instead of refund, is that the 10" fine/extra fine stone works very well, as does the Coarse side of this stone. So, I tend to believe that this is just a quality control issue, sending out a bad stone and that the replacement will work properly.I've never used a diamond stone before and the ones that I have, that work, are very nice to use. Given the cost, they should work very well. With the exception of the bad side, I think that these stones are a good value. The fact that they remove material quickly and well and stay flat while doing so, is a significant improvement over normal stones.So, in spite of the bad stone, I would recommend these stones. They're well made and nice to handle.I'll update this review when the replacement stone arrives.

While I think that this is a good sharpening method, note that you can not use the bench stone to flatten other sharpening stones. You might be able to get away with flattening a softer stone, but using it to flatten a harder sharpening stone ruined the extra course side of the diamond stone. It still feels rough, but it does not cut very well. Trying to sharpen a wood chisel on the damaged extra course side showed very little progress. I made much more progress (it went much faster) using just the course side which was not damaged since it was not used to flatten other sharpening stones. I do not know if the sharp edges of the diamond were somehow damaged or if they broke loose, but the stone would not cut. Very few, if any, small shavings (swarf), formed when using the damaged side and it took forever to show any progress when creating a new edge.

I like a sharp knife but I am far from an an expert in tool sharpening. I had a couple of fairly expensive knives that I could no longer sharpen with the stones, steel rods, and ceramic sticks that I had traditionally used. I decided to invest in a diamond stone. This DMT bench stone works great and the fine/course combo has been good to restore my dull knives or tone those that were in better shape. I liked it so much that I also bought a small pocket model and and a rod by the same company for serrated blades. I am using it in the available plastic base and I think that is the way to go. I have sharpened every knife we own, my axes, all my tree and shrub trimming equipment, and I used the diamond bench stone to flatten my old sharpening stones that were grooved from use. I am glad that I bought a larger size for all the things I have sharpened. It is easy to clean with soap and water. A solid tool investment.

The advertisement clearly states the sharpening stone comes with a base. The stone arrived without a base. Please send a base to the same address as the stone was delivered.

It’s DMT say no more

Received stone damaged

OK. Overpriced for what it is. You will need a method to hold the stone in place. (It is not a stone, but a piece of plastic covered by diamond encrusted metal grill). The rubber mat that comes with it for this purpose is poor quality.

Es brauchte auch bei mir 3 Anläufe bis ich einen Duosharp erhalten habe der wirklich unbenutzt zu sein schien (meine persönliche Einschätzung)Ich habe den grob / fein Duosharp und kann nur positives berichten mit etwas Übung bekommt sicher jeder eine brauchbare bis sehr gute Schärfe ans Messer... Das Endergebnis ist natürlich von vielen Faktoren abhängig vor allem das die schneide nicht nach innen gewölbt ist, zb übertrieben, wie ein schäl Messer, das geht mit diesem Schleifgeerät nicht. MAN kann nur gerade und gewölbte (nach außen gewölbt vom messerrücken aus gesehen) Messer / Klingen damit gut bearbeiten.Schaut euch die zahlreichen Videos auf den bekannten Plattformen an wo auch alles erklärt ist was die Voraussetzung ist um ein Messer zu bearbeiten.