Diamond Machine Technology (DMT), 8-in. Diamond Dia-Sharp Whetsone Bench Stone, Extra Coarse Grit Sharpener (D8X)

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.

The media could not be loaded. 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 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.