Double bevels and thinning the blade

This is a general question I have about double bevels. How can I tell if the knife, or knives that are soon to be bought have a double bevel? I have read that Dave offers thinning the blade and re establishing a single bevel. Why would you need the blade to be thinned more than offered, and why is the double bevel not preferred?

I have also been reading about honing a knife. I have read that if you have a double bevel, you should be honing both bevels to remove steel more even. Is this accomplished by increasing the angle while honing thereby working on the secondary bevel?

 

Isaac, I think there may be some confusion on your part with terminology regarding what makes a knife single-bevel or double-bevel, what primary and secondary bevels are, and general sharpening technique as well.

Generally, Japanese knives identified as a deba, yanagiba and usuba are single-bevel. These knives have a chisel-type grind, where one side appears to be flat (it is actually slightly hollow-ground) and the other side has the bevel.

Knives identified as gyuto, petty, sujihiki or santoku are double-bevel. Both sides of the knife are ground with a bevel, thus the name "double-bevel".

Here's a simplified drawing of the two types:



There are exceptions, but they are of little consequence at this point. For some reason, certain knife makers (Carter, Takeda and Konosuke, to name three) use the single-bevel names for double-bevel knives which causes some level of confusion.

Now there is also the unfortunate convention of also describing the geometry of a blade, either single or double, in terms of bevels, and I think this is where you are getting confused.

Here's another illustration showing some of the possible combinations of bevels:



Most of the knives used in the kitchen have some form of a compound bevel, or a convex grind with a small cutting edge bevel.

I think you have misunderstood what you have read about what thinning is. It has nothing to do with "reestablishing" a single bevel. It is the process of removing metal from the blade above the cutting edge to make a cross-sectional geometry that will move through the food you're cutting with less resistance. Many factory made knives are compromises between a thinner grind and a more robust grind that allows for a certain amount of abuse, and thinning these blades will make them better cutting knives.

You may want to do some research to find articles and videos that explain these concepts in depth. A good place to start is an article by Chad Ward on general knife maintenance: http://forums.egullet.org/topic/26036-knife-maintenance-and-sharpening/

You may also find Jon Broida's videos helpful: https://www.youtube.com/user/JKnifeImports?feature=mhsn#g/u

 

Great info Rick:cool1

 

Thank you for the post Rick :like