Knife sharpening & maintenance
Wüsthof honing steels
Every knife becomes (slowly) blunt after first use and must be sharpened again in time. By sharpening the knife regularly you can ensure a major sharpening session is delayed as long as possible.
You can do that with a honing steel (or whet steel). That is a steel with vertical ribs. You sharpen the knife by moving it a few times along the steel, which has to be longer than the knife. It must also be made of harder steel than the knife. VG10 for example, a steel which is often used for high quality kitchen knives, is too hard for a honing steel. By using this you don't do a favour to your knife or honing steel.
Honing steel or sharpening steel?
A honing steel removes any burrs off the cutting edge. Burrs are the first indication of a blunt knife. They are difficult to see at first. When burrs become larger you can see a glittering on the edge. A honing steel removes the rougher burrs and lifts the small burrs. That improves your knife edge.
A honing steel only removes burrs, and no material from the knife. The knife thus still becomes round and blunt on the edge. A sharpening steel, diamond or ceramic, does sharpen the edge. They remove a layer of steel from your knife which shapes the cutting edge of the knife back into a V-shape. A diamond or ceramic sharpening steel is also quite a lot harder, which means you can actually sharpen any knife on it.