Hardness vs performance

[Mark Reich]

Thanks a bunch, Gentlemen.    I'm happy you appreciate this on your Forum, Mr. Mike.

Mr. Jan, that is quite a statement, coming from you, and gives me pause. I won't wax philosophically, but I can say that almost every knife is hard for me to trade for money.

Another thing is, it's most natural for me to say is something like...

"Here's a picture of her brother."   
   

I'm happy this is original to you as well, Mr. Me2. Yes, I've heard what you describe, but I don't remember how the blades looked, and I don't remember trying that. It doesn't sound like 52100 would work that way, and I honestly don't know much beyond the basics of many other steels.  

When I realized Japanese steel wouldn't be practical, I basically chose 52100 because I thought it was high quality steel with enough carbon. Mr. Ed Fowler taught me a lot about mindful forging, grain refinement, and "listening to the steel". It may sound silly, but that's a pretty down to earth description of "figuring out how 52100 works" IMHO. 

I really haven't payed much attention to what anyone else does. I have tried to study blade metallurgy pretty hard, and incorporate the things that are known to have the best affect on steel. I've tried so many different things, and just hold on tight to the positives, and remember the things that worked and came out well.

I'm blessed to be able to make good looking knives, and fortunate they perform to my highest expectation.

[scott.livesey]

I have the feeling that a knife could vary several RHC points over the length of the blade.  Is that correct?

it will depend on the hardening process.  I heat the entire blade to the same temperature then quench the entire blade.  on some blades I tested 10 to 15 different spots and usually had less than 1 point of difference in the readings.  example highest of 65, lowest of 64, average of 64.5 with 12 spots tested.  a lot of flex is determined by geometry.  i make fairly high hardness blades, usually Rc63-65, using low alloy fine grained tool steel (O1 and O7).  blades for the kitchen.  if dropped on concrete, the tip would probably break off.  very small edge angle, usually less than 15 degrees total, with a 10 degree per side microbevel.  they can slice boneless protein and 'soft'(nothing harder than a potato) fruits and veg see thru thin.  they will go 6 to 8 months between touch-ups on a diamond hone.
the big issue is that there is currently no test anyone can do to show performance.   a BESS score is just a measure of sharpness, i don't know how that correlates to slicing ability.

[EOU]

We can answer that one Scott. A BESS score won't tell you anything about how the edge slices other than to assume a sharp edge will generally slice better than a dull one. Bess scores won't tell you much about the quality of the edge either be it toothy or otherwise. We're working on that though via our test stand.