This is a re-post of sorts. I already put this on another thread but thought if anyone had subscribed... Sorry I was sidetracked- I hate my job. Here:

I've been meaning to do a good post on sharpening but... Ugh! I'm sorry, guys! This will be quick and dirty...

Okay- first rule is not to let you knife get too dull to begin with.

Next rule: the final angles of the blade will be dictated by your intended use. The narrower the angle, the more delicate the edge is.
- a wider angle (say 25-30 degrees) will give you a not extremely sharp but very solid, durable edge, like on an axe.
- most knives like what we talk about should be sharpened between 18-25 degrees, most are 22.
- A cooking knife needs to slice and isn't expected to hit such hard material, so they are sharpened at 10-20 degrees
- Razors, scalpels etc are sharpened at as close to 0 (zero) as possible- they cut like the dickens but if they touch the wrong thing at the wrong angle, the edge will bend, fold or chip.

okay- most experts agree (at least the ones I read) that your blade should have 2 bevels at the edge. We're talking at the near-microscopic level here- you can even see it in the pics above.

One angle/bevel is the primary. This is the edge you can see as you look at the blade. Your knife blade comes from the spine, getting thinner and thinner until there is this angle, which plunges to meet the other angle, making the sharp edge. If the primary is too wide- the blade won't cut well. If its too narrow, the edge will be too brittle or thin and... see above.

Once you have a primary bevel, you need a secondary bevel that is a little wider than the primary. Its wider because we want it to be strong while still allowing whatever you're cutting to "flow" by the bevels without getting hung up. Take a look at this representation of an edge at the microscopic level:



Note in the above illustration the angle is listed for illustrative purposes- it may not be accurate.

In the illustration, the secondary bevel is listed as 20 degrees. The Primary is smaller- let's say 16 degrees.

This combo of 2 bevels gives knives the sharp edge needed while still leaving enough metal "behind" the edge so as not to buckle or crack if the blade comes into contact with a hard material.

Remember that the more surface area you're grinding, the more metal you're wearing away. It will take longer to sharpen larger surfaces. Imagine your kitchen counter top was a knife edge. If you take a file to it at 45 degrees, you'll really be cutting into it, but as you get deeper in, the file has to cut a larger surface to do the same work. Same thing with the blade edge. One common complaint is "I used to be able to get it sharp- now I can't." This is because the secondary and primary have merged. You need to "scale back" the primary, then add the secondary. Let me know if this needs more explanation. Its 3am right now and I'm fuzzy.

Worried yet? Consider this: The "ideal angle" of any blade will vary based on 1) the blade steel used 2) the hardness 3) the tempering of the blade 4) the intended use. For example, Imagine we could make a bunch knives exactly the same shape, size, grind, but with 2 different steels, and we intended to use them for the same purposes. If we use AUS8 steel, after some trial and error we'd find we had to grind it to a certain bevel that might be slightly different than the same knife with a blade made of 1095 or ATS-34. We might get the same results (a sharp edge that cuts), but the angles would be slightly different.

How do I get the d@mn thing sharp?!!

There are a ton of ways. Mostly- practice. One good practice technique is to use a marker- any one- and mark up the edge of your knife with ink. Then you can more easily "see" how your blade is being sharpened on the stone. Also remember that its a big sense of "feel" to get it all right. Lastly, you can often use the existing edge as a guide- this is where using the marker really shows.


All knives are sharpened through wearing the metal away from the edge to make as perfect a "V" edge as possible. We use stone, diamonds, and ceramics because they "cut" the metal away as they move on it. You can use many "grits" of stone- from extra coarse to ultra fine, but generally its easiest to start with medium (see rule 1!!!) and then go to a fine stone. I often follow with an ultra fine stone when I want a truely razor sharp edge.

Regardless of how you oreient your stone (verically, horizontally) you're bringing the edge to the stone at a consitent angle all along the blade. You do this by setting the edge on the stone and elevating the BACK of the blade until its at the desired angle.



This takes practice. Many sharpeners come with various forms of guides or a clamping system to maintain the angle.

If you don't maintain a consistent angle:
1) your edge will be uneven, and will dull sooner
2) your edge might never get sharp because you'll keep "rolling" the edge or not be working the edge- or both!!



Most people just use a cutting motion, like you were trying to slice off the top layer of the stone, but you can also make circles as well. Most people work on one side of the edge for a few minutes, then the other.



The purpose is to get the 2 edge angles to meet exactly in the middle.

Once they start meeting in the middle, the very microscopic tip of the edge will begin to bend away from the sharpening surface. This is called a "burr" or a "wire edge." It is also called "false sharp," because it will feel sharp to the touch, but as soon as you use it, the edge dies.



You can't always see the burr- but you can feel it. The safesy way I find the burr is to scrape my fingernail down the edge to see if it "hangs" as it touches the edge. In the above image, imagine my fingernail sliding from right to left, with my finger away from the blade.


Once you have a good burr, you're almost done. Now is the time to slightly change your angle, and change your stone to a finer one.

Increase your angle just a little, and work the knife a few times on each side, always maintaining the new angle. Once you get really close, you should be using lighter and lighter stroke- you're coaxing the last burrs off the blade, not bending the edge you've worked so hard on.

Once you've got it sharp, clean up what needs cleaning and go use your knife!

Did I leave anything out?