[chrisbelgium]

Here's a real situation that may help a little more. Many Japanese knives are delivered just a little sharpened on one side and a minimal deburring on the opposite side.

The picture on the left shows how this carbon knife came. You can clearly see it's almost 100/0, but was probably 99/1. This is factory sharpening on just one side which is called single bevel.

Let's simply agree for clarity that a double bevel is sharpening on both sides. A V-edge is a double bevel with a 50/50 repartition and even less seen in Japanese knives than an albino rhino.

Don't worry about the numbers 70/30, 80/20 or 99/1, they are no less than estimated values.

The other 2 pictures are somewhat irrelevant for you right now. Let me add perhaps that this knife was "thinned", which means that the part that I marked with A and B has been grinded away. In this stage it's still single bevel sharpening, but, at a very low angle. Normally you would go to a 15° angle for Japanese knives. The moment you start to grind on the other side, it's turning into a double bevel.

Let me also add that you will always end up with slightly convexed bevels. Simply because noone can ever hold a knife that fermly -while making sharpening movements- to get a 100% flat surface.

 

[chrisbelgium]

Now, on the angles to produce. Many people will tell they sharpen at 15° or 10° or whatever. The very thruth is they have no clue at all! Not that it matters that much. Later on, when you have acquired some experience, you will automatically go to an angle that suits you best naturally, even without knowing the exact angle. I strongly suggest to keep that angle and none other. Consistency in sharpening is the key-factor for success!

Anyway, I made this little chart a while ago, it has been posted on KF and FF too. A very simple thing to find out exactly at what angle you are sharpening at, or to adjust the angle for any particular knife. All knifes are all different. It's a good thing for sharpening novices to check how good you are at estimating sharpening angles.

How does it work?

Measure the height of your knife from the heel to the spine. Let's say a 240 mm knife you measure has 50 mm height at the heel. Look 50mm up in the left column. Now, follow the row to the right untill you reach the place where the top of the column appears 15°; you will find 12,9 mm. This is the distance the spine of your knife should be above the stones.

You may have to click on the image to see it full size. Please feel free to download and print it. It's quite helpful.