Cutting angle – With a manual stick or sharpening stone you set the angle yourself so this does not factor into the equation when choosing that type of sharpener. When shopping for an electric sharpener however it does. You’ll want to decide if you want your knives to have the 15 degree “Asian” style angle so that you can make precise cuts or the Western standard 20 degrees or 22-degree sharpening angle. Most people will opt for the 20 or 22-degree angle simply because their cuisine doesn’t call for a lot of finesse from their knives and those knives are probably of a heavier Western variety anyway.
There is no dominant standard for the relationship between "grit size" and particle diameter. Part of the difficulty is that "grit size" is used to refer to the smoothness of the finish produced by a sharpening stone, and not just the actual size of the grit particles. Other factors apart from particle diameter that affect the finish (and thus the "grit size" rating) are:
You will also need at least one finer stone. Once the shape of an edge is established, successively finer grits are used to refine the edge improving the quality of the cut it delivers. A dull edge will not cut well and should be shaped with a coarse stone. An edge sharpened on a coarse stone will cut better than a dull one, but still won’t be ideal and should be improved with a finer stone. As you progress through finer stones, the cutting edge will continue to improve. How many and how fine these stones need to be varies depending on how fine an edge you require.
This wedge ends up short of a "point" to a much larger degree than the picture would indicate. The metal stops short, but then there is black non-slide "tape" applied to one side, and white "slide" tape applied to the other side, which makes the wedge even thicker than it appears in the photo, which means that in practice the end of wedge is even more truncated. So I have a hard time supporting my knives accurately on this wedge while sliding them down into contact with my stones. Prior to buying this wedge I just used a wooden wedge I cut off of a 3" by 3" post using a miter saw, said wedgewhich has a much less truncated end. That wooden wedge unfortunately absorbs water from my Japanese Waterstones. But I will try spraying polyurethane on that wooden wedge to help waterproof itand try again. If that doesn't work I will try to find a 3" by 3" plastic trim board somewhere and cut a wedge off the end of that. Note that you can buy 20 degree plastic wedges, but this is the first one I have found that does 15 degrees (nominal.) Note that Amazon also has the Blue AngleGuide set of wedges, but they are very small https://www.amazon.com/Angle-Guides-Sharpening-Knife-Stone/dp/B01N4QMO7U/ref=sr_1_4?ie=UTF8&qid=1499301705&sr=8-4&keywords=sharpening+angle+guide
The most important aspect of a sharpening stone is the grit. If you have knives that have taken a beating and are either nicked up or really dull, you’ll need a courser stone to get it back into shape. And in order to put an exceptionally sharp edge on an already sharp knife, you’ll need a finer grit stone. If your knives are already in pretty good shape and just need a touch up, buying just a finer grit stone might be enough, but don’t think you can get away without a courser stone for knives that need more TLC. It is possible to buy a combination, or two-sided sharpening stone.
A: That depends almost entirely on how often you use them. If you are a professional chef who uses his or her knives every day then you should hone them every time you use your knives. But honing has its limits and over time your edge is going to become dull no matter what. Therefore your knives will need to be sharpened at least several times a year. Some chefs, in fact, will use a whetstone on an almost daily basis in order to ensure their knives are always razor sharp. Most of us, however, are not professional chefs and may not even touch our kitchen knives for days at a time. In that case, it’s probably a good idea to hone the edge after every couple of uses and have your knives sharpened once a year.