Chef's Choice Chef'sChoice 4640 Versatile Professional Angle Select Diamond Hone Manual Knife Sharpener for 15 and 20 Degree Edges, 3-Stage, Black, 10.3 x 2.2 x 7.2 inches

This is simply a great sharpener. I've had to use extremely sharp knives most of my life, as a musician who makes reeds. That got me acquainted with the finer points of sharpening, which I always thought could never be accomplished with a "contraption," but had to be done by hand with a flat stone. This has proven me wrong. This brings my carbon steel kitchen knives to an edge that rivals the razor sharpness of my reed knives. The real test of sharpness isn't a tomato or carrot, but a simple piece of a paper towel, held on edge. A sharp knife should be capable of dragging across the edge of a paper towel, folded a little to give it support, not pushing it out of the way, but slicing a clean cut right through it. Knives sharpened with this device can do that.This has a 15° slot, a 20° slot, and a rotating stone for honing the edge. The first time you use it, your knife will have to adjust to the angles of these stones. That may take anywhere from 50 to a hundred fifty strokes, depending on how different they are. Once that is accomplished, you can usually get an edge back to its fine sharpness with less than 10 strokes.One of the keys to getting a good edge is holding the knife straight as you draw it through the slots. Get your shoulder, elbow, and wrist aligned so that you do not put lateral forces on the knife. Drag it straight, back and forth. Don't use too much pressure, and don't get in a hurry. Listen to the stone. Your ears will tell you more about your edge than your eyes. The sound and feel will change as your edge begins to reach its maximum sharpness. Again, remember that the first time you will have to stroke it until the excess metal is removed, allowing the edge to match the angle of the stones. Until you reach that point, the actual cutting edge is not even making contact with the stone, so don't think you can shortcut this step. Once you reach that point, it will only take a few strokes to get the edge back after each use.When you have sharpened the edge as far as you can with the angled stones, you will find that there is a remaining "lip" to the edge. Dragging a fingernail backward across the edge, you will feel it catch on this lip. (be CAREFUL if you try this. Knives can get incredibly sharp. One slip the wrong direction, and... well... you'll find out what sharp knives can do to soft fingers!) To remove this lip, lightly roll the blade through the rotating stone, and it will hone it smooth. NOW you have a knife that is incredibly sharp.One bit of advice. This has a wonderful handle. Push down lightly on it, enough so that it won't tip, but KEEP YOUR THUMB BEHIND THE WALL OF THE HANDLE. Don't place it under the slots! The knife will come out of the slot, fall abruptly and cut your thumb! Just keep it back under the handle, and you'll be fine.Excellent sharpening device, apparently designed with attention to detail. Very highly recommended!

Very easy to use and gives your knives a good edge if you don't want to learn how to use a polishing stone. It does take a bit of work when sharpening knives the first time because you have to put the correct angle on the edge, but afterwards they only need a few strokes to sharpen and polish.

This is my second one of these. They work as advertised and are by far the best sharpener I've used. They are easy-to-use, and don't require a lot of fuss to get a good edge on most of my kitchen knives.

I like that there are slots for two different blade angles. They even have decent instructions on how to use it. They are so helpful, I keep them with the sharpener. I also like the fact that the touch up slot can be used to tune up serrated knives. That's a bonus I didn't expect. The sharpener has some heft to it and the rubber bottom makes it stable during use. I used a Sharpie to write the directions on the sharpener about how often to pull a blade thru when using it, so I don't have to look it up each time. The only thing I wish it had is a way to sharpen my scissors. I knew it didn't when I bought it, so I can't fault the manufacturer. I guess I just need to buy one just for that purpose.

I own the Trizor Diamond edge electric sharpener by Chefs Choice, which I love. I wanted a small, portable option for my Mom who lives abroad and can’t use US appliances. This works great and takes the guesswork out of knife sharpening. It just requires a lot of work for really dull knives, which the electric one handles with ease. Fabulous option for campers, vacation homes etc. where only occasional use is needed. Will take a 20 degree blade to a sharper 15 degree, if desired.

Not as good as I had read with other reviews. Maybe it's just me, but I have trouble holding my knives perfectly vertical for a truly keen edge.

I first saw this sharpener on a test kitchen show. This was the best sharpener tested for the value. It has diamond sharpening wheels!

The model 4640 design is flawed. I had several years of excellent service from the older model 4643 and made the mistake of buying the cheaper 4640 as a replacement. The 4640 uses fixed plates and the metal side guards are so close to the slot that they scratch against the knife edge. Bottom line - The 4640 does a lousy job and if you hold the knife blade just 1 mm out of level the cutting edge will scrape against the metal side guard and ruin the edge. I returned the 4640 and bought another 4643, which has a much better design, is easy to use and sharpens smoothly in just a few seconds per knife.

Excellent sharpener for European or Japanese knives. Good price.

It sharpened my knives easily ,would recommend

Works great. Simple and effective.

function well, as expected.

Does not improve the sharpness of knives. Useless tool.