Sharpening knives might not be rocket science; however, it really is beneficial to know what type of edge angle and the hardness of the blade to accomplish that razor sharp edge most of us want. Most European knives have an “Edge Angle” of 15 per side, Asian styles are 10 per side. The “Rockwell Hardness,” determines how well a blade will retain its edge and the harder will hold the edge longer. However, will also require more time, a harder sharpener, and harder sharpening steel. Any sharpener or steel with a hardness rating less than that of the knife blade, just isn't going to work well!
I actually have some fairly good and semi-expensive knives. I bought a set of J.A. Henckels for the kitchen quite a few years ago and they finally got so dull I decided to sharpen them. After spending a fair bit of time on the first knife with a Rockwell Hardness of 58 and using my hand-held sharpener with a
20-degree V slot that did NOT even phase it, I decided it was time and actually bought one of those upper-end “Professional” Chef’sChoice sharpeners just for that set J.A. Henckels, plus all the rest collected and thrown in my kitchen knife drawer over the years and do recommend, "IF" one really has the need!
If sharpening a “soft” blade (and that doesn’t mean cheap), I would suggest just about any sharpener will work. I can attest there are sharpeners out that that will NOT work well with a knife having a Rockwell Hardness of 58. The “Professional” Chef’sChoice will do the job, and add it will take closer to 4-5 passes in each stage to come close to a razor edge with a 58 hardness rating. Would highly recommend “IF” you have a lot of knives needing edges restored. Emphasis the “IF” you have a lot of knives. If not - My advice, save your money and don’t buy ANY other than a good hand-held and sharpening steel.
After restoring the edges on my knives the Chef’sChoice now spends most of its life stored away. The only time it sees daylight is when I need to restore an edge on the J.A. Henckels. Quite honestly if I was to do it again, and would recommend, just by a J.A. Henckels hand-held sharpener with the Rockwell Hardness rating of 66 and sharpening steel saving those $$$. Again, unless you have a lot of knives that needs edges.
For most good knives with soft blades, just go out and buy any good hand-held sharpener with a 20-degree V slot and do it by hand. If it is "chew the chit out of an average knife" you are using to much force and if you have a "good knife" with a hard blade it probably won't even put the edge on it, unless it is harder than the knife blade. A good "hard" hand-held sharpener will regrind and hone the edge of any blade just as good as any professional sharpener. All that is needed for a "hard" blade is to draw the blade through the V slot 4-5 times with "moderate" force, then use lighter force until you get that razor edge you can shave with. For the "softer" blades use "lighter" force. From there both can be finished with the sharpening steel, as needed to retain that edge. Surprisingly I have found most don’t know how to properly use either. The key and very important is that 20-degree angle.
When my fillet knives, with soft blades need an edge and are "good knives" I actually use my hand-held V sharpener, which has four "rolling" steels. Finishing with a sharpening steel when needed. I do like to keep them razor sharp and here is exactly how I use the sharpening steel to do that. This is also the way Henckels website states:
1. Place the knife blade against the tip of the sharpening steel at an angle of approximately 20 degrees.
2. Pull the knife down and across the steel, describing a slight arc.
3. Repeat this action on the back of the steel to sharpen the other side of the blade.
4. Repeat steps 2 and 3 five to ten times, alternating the left and right side of the blade.
It is very important to maintain the angle of 20 degrees and to run the full length of the cutting edge along the steel from the hilt to the tip of the knife. Speed of movement plays no part in this process.
Just my two cents!