Hardness for sharpening with a steel?

[F. Allin Kahrl]

I'm making a couple of A2 kitchen knives as Christmas gifts and the people who will receive them use sharpening steels in their kitchens. How hard should I make a blade so that a steel will work on it?

Thanks.

-Allin

 

[mete]

My Shun knives are easily sharpened with a steel - VG10 at 59-61 Rc

 

[Joe Cabaup]

I know the answer to this one!!!

The steel isn't used for sharpening at all. It is to straighten the wire edge.

This is the explaination handed down from my great grandfather, a Cordon Bleu chef at the Four Seasons in NYC. He was, in turn, taught by his father and grandfather, a chef to King Louie in France (so the family legend goes.)

Kitchen knives are left with a slight wire edge (burr) after sharpening. Instead of stropping or buffing the edge, the wire edge is "steeled" to align it with the rest of the blade so the blade has a super keen razor edge. This will last long enough to prepare the food. It must be steeled again before use.

Unfortunatly, kitchen steels today are sold with striations or in a stone material to "sharpen" as you steel the edge. I don't feel this is necessary and may ruin a good edge.

With the modern steels and heat treating methods, I don't feel kitchen knives need to be steeled, unless you prefer to sharpen the old way. There is something theatrical to steeling a knife before carving the Christmas ham or turkey.

When I make my kitchen knifes, I put a slight convex edge on and give the edge a run on my buffer. One L6 chef's knife that I gave my father Father's Day 2004 is used daily and it is still cutting paper thin vegis and meat with no need to be sharpened or steeled yet.

I haven't measured the hardness of the L6 knife but it does pass the brass rod test.

 

[brash]

A few things:

- As was mentioned, steeling is not sharpening. A steel only straightens the edge. A steel with striations will make micro-serrations on the edge, which some people like and some people don't (I'm with the previous poster). Steels are used to prolong the time between sharpenings.

There are also steel-shaped objects designed for "sharpening," such as the so-called "diamond sharpening steels." If the people you are making this knife for use these... well, all I can say is they don't deserve a custom knife, because they are just going to damage it. I would kindly suggest that they think about buying a decent sharpening system, or (ideally IMHO) a set of waterstones. Their knives will thank them.

- You don't need to worry about a knife being too soft to steel. You might, however, worry about it being too HARD. If an edge is both hard and thin, a steel can ruin the edge. Many people do not steel traditional Japanese knives because of the hard, delicate edges on these knives. You have to be very careful (use no pressure, just the weight of the knive, if that) when steeling knives with hard, thin edges.

On the other hand, you are making this out of A2, and I believe A2's max hardness is somewhere around 60rc. And I suspect you aren't going to be sharpening it for them at 10 degrees per side... So you don't need to worry about this.

 

[Protactical]

I have seen old sets of carvers from the heyday of Sheffield, and they seem to all have striations on the steels they were sold with. When "sharpened" the steel was always worked on both sides, while the wire edge would presumably only be on one side, and all the back and forthing would tend to remove it. I also doubt a wire edge last for years.

I have heard the wire edge explanation, or edge setting explanation, and it is what is done with cabinet scrapers and the hardened rods that set them. Not sure what hardness the average cabinet scraper is, not hard like a chisel. But they can be multiply reset, between sharpenings, by cold working a new burr. The burrs last only a short time, but do a lot of work on wood. So the knife edge resetting might be possible though the tool that comes with carvers is far more like file than a burnisher.

The other thing I have heard said about carving knives is that the butcher is after a rough saw like edge, that is very much like the edge a file puts on. Filed edges can farry from smooth to lots of wire, to serated, depending on the file and technique.

A simple way to proceed if the "steel" you have is like a file, try cutting some less visible portion of the cutting surface, like around the end (not the tang, it probably will be soft). See if it is file hard. Try cutting with the grain of the steel, so that the two files don't just snap each other's teeth off. If the steel skates the file, then just do your L6 to a level where it can be worked by a file.