DMT D8X Diamond Dia-Sharp Bench Stone, Tool, Blade, Knife Sharpener - Extra Coarse (220) Diamond Grit Flat Sharpening, Made & Crafted in the USA 8" x 3" x 0.38"

Sharpening has three steps... 1. Getting the right shape/angle on the blade, 2. Sharpening to a very fine edge, 3. Honing from very sharp to extremely sharp. This extra coarse stone is great for shaping the blade. For example, I have a kitchen knife that was messed up by a grinder - the middle didn't touch the cutting board. In just a few minutes this extra coarse stone straightened the blade and got a good bevel along the length. It still needed to be sharpened with the DMT Coarse and Fine, but with the cutting edge of the blade straight and the bevel good, sharpening was quick and easy. Example 2. I have a 1 inch woodworking chisel that I had messed up on a grinder (bad angle). I had spent a huge amount of time (over an hour) with a coarse DMT stone getting it partially fixed - from a crooked 30 degrees to 28 degrees. Now that I have the extra coarse, I got it to the desired 25 degree bevel in minutes rather than hours. Yes, it took quite a while, but nowhere near as long as I had already spent doing the first part of the job with the coarse rather than extra coarse stone. Some of the other reviews said the plate was not flat. When it arrived I immediately compared it with my three other DMT diamond plates. The plate was flat (or I would have returned it). As I first used it, I could hear a slightly different sound the first time over each area of the stone. No surprise, it had to be broken in, so I made sure I covered the whole area. A couple small spots were still rough after the first pass, but were perfect after I ran the chisel I was sharpening over that spot 3 or 4 times. No big deal. Overall I highly recommend the DMT extra coarse for shaping a blade (kitchen or woodworking). Much less likely to mess it up than on a grinder (or in my case, I was able to fix the blade after messing it up on a grinder) The DMT regular coarse is excellent for the first sharpening - removing the scratches that naturally come from using an extra coarse stone. I originally got this coarse stone to flatten my waterstones - it does a good job of that, but is useful beyond just the waterstones, when I have to do serious sharpening work on a neglected blade. The DMT fine (there is no medium) does a great job sharpening kitchen knives (at least razor sharp), and taking my chisels etc to the next level. If I am just touching up a sharpening job, this is where I start. Kitchen knives rarely go beyond this level. The DMT micro fine was a disappointment for my chisels and planes. Instead I go to waterstones - 4000 grit then 8000 grit. Those give an almost mirror finish to the chisels. I called it a mirror finish until I got a 13,000 grit waterstone. Now that is my standard of sharp, for both the front and back of my blades.

This stone has truly elevated my sharpening game. About two years ago, when I first began learning to sharpen, I did my research, and the advice I kept seeing was, "you only need a 1K grit stone." So, I went with a Chosera 800, which is reputed to be closer to 1K. The issue is, when you’re just starting out, you’ll likely struggle with holding a steady angle and may end up mangling your edges. With a higher grit stone, you’ll need more passes to set a proper apex or fix mistakes, which only increases your chances of errors. This was my experience, I found it nearly impossible to hold a consistent angle over 20-30 passes. The more I slipped, the more passes I needed to correct it, leading to a frustrating downward spiral. Eventually, I could achieve a passable edge, but it wouldn’t last, and I had trouble spots everywhere. I decided to take a chance on this low-grit stone to undo the damage, worried it might make things worse, but the results were surprisingly positive. Right away, I felt this stone cutting, and after just a few passes, I could see a significant improvement in my primary bevel. I followed up with the Chosera 800 and a basic chromium oxide strop, and I had created my best edge yet! Motivated, I upgraded my setup further, adding this coarse stone, a Chosera 3K, and a new strop with 3-micron diamond paste. Now, I can reliably achieve edges that pass the "paper towel test." For the first time, I have what I’d call “scary sharp” edges. I can even cut a tomato horizontally, hands-free, without it rolling on the cutting board - I never thought I'd see the day! It turns out, my issue wasn’t so much about holding a 12/15/20-degree angle, it was maintaining it over hundreds of passes. Now that my knives are properly re-apexed, touch-ups with the 800, 3K, or even just the strop are simple. Even if I don’t need to use this coarse stone often, I’m thrilled to have it in my setup, and now I’m wanting to sharpen everyone’s knives, so I’m sure it’ll get plenty of use!

I've been using DMT products since the '80s. These Dia-Sharp 8" are my mainstays. Once broken in, they grade fairly and just don't require the maintenance of other stones. If you have the range (after the Medium-Extra-Fine I have them all) you can tackle anything. The 4000 (6 micron) has been a hole in this line for a while, it's nice to see it has been filled. As delivered, these stones have a lot of manufacturing "gunk" on them, and when new can be pretty sharp, i.e. grading lower (coarser) than marked. The stones break-in with use, and I actually break them in before using on anything of any significance. To break these stones in and clean them up, spray with 50/50 solution of Simple Green and Water. Use this as a lube for the stones all the time, it just works better than water or dry. Take a hardened piece (nice if it is the width of the stone) of 440C (I use a old knife tang) and run it up and down the stone, in circles or whatever, but try to cover the whole area. Keep adding Simple Green as needed, wipe the stone and steel off when it gets dirty (it will) and you should start to feel the stone smoothing out. There are little pieces of dirt and manufacturing eccentricities in the coating they put on them and you need to work that off. Once that is off, the stone will exhibit a much more uniform texture that you would expect. At the point that the surface is uniform, the stone will still grade a little rough, but will smooth out with use. Keep using the Simple Green solution to keep the stone and work clean. When breaking-in, pay significant attention to working the edges of the stone, this is important as this area can be a little rough. Even using the Dia-Lap 120 to chamfer the edges doesn't work all that well. If you are lucky enough to have a stone that they didn't get coated all the way to the edges, don't send it back; I wish they made them all that way. The stone should exhibit a uniform gray/silver appearance when properly cleaned and broken-in.

I am accumulating more and more DMT sharpening stones and I would recommend others to do the same. I started with a coarse and a fine grit which got my tools 95% of the way there. The coarse grit was used to set the angle and I polished it up with the fine. A few strokes on a leather strop and near razor sharpness. I bought an extra fine grit stone to see how much sharper I can make my knives. The point is that you can get really sharp blades with just one or two stones. I recommend the DMT stones basically because they work and should last a lifetime for the average user. They are made in the USA, come with great reviews, and I really like the results. I have lots of natural stones in my toolbox but modern steels can sometimes be difficult to sharpen and I don’t think I have used them in years. There is no question that diamond sharpening stones will sharpen any knife with a lot less time and effort, not to mention that you don’t end up with a huge mess afterwards.

I received the stone and began using it today. I needed to remove a lot of material from very hard steel chisels to flatten them and restore their edges, and it performed very well for this task. I am considering purchasing a finer grit for more precise sharpening. The stone is mounted on a heavy, stable piece of steel that prevents movement or slipping. It was well packaged, with no damage to the box. However, upon inspection, I noticed the stone had a small dent, likely from a drop at the factory before packaging—it's visible in the photo but not significant. Aside from that, I am satisfied with this stone and plan to buy a finer grit version to achieve even sharper edges.

Good for fast removal of nicks if you lack a grinder. Zero maintenance doesn't require flattening like a waterstone.

Excellent stone! If I need to reproflile an edge this stone knocks it right out. The edge looks clean and well balanced. I have the extra coarse, coarse, fine, & extra fine DMT diasharp stones and highly value each one.

I use three sharpening plates; the extra coarse, the fine and the extra fine. The extra coarse has quickly gone from too coarse to just right where I expect it to stay for a long time. About fifty years ago I was using oilstones. About forty years ago I switched to waterstones and they were a tremendous improvement. Recently I finally switched to diamond plates and I'm sorry I waited. They are a vast improvement over waterstones; far faster, much cleaner, and virtually no maintenance. The three DMT plates that I bought seemed virtually flawless. There is a very small bare spot on my fine stone, but it is of no practical consequence. I can't compare DMT quality to any other brand because I have tried no other, but I can say they are flat and effective and I hope they will be durable. Sharpening is no longer a chore, so now I keep my tools sharper than I did and of course that makes a tremendous difference in one's work. They are the best thing I've done for my woodworking in a long time.