It seems that discovery just breeds more questions. What's got us thinking this morning is this definition of hardness "Hardness may be defined as a material's resistance to plastic deformation." We found the first reference to this definition in a 1890's patent application for a means of testing hardness. A very cursory search makes it appear that this definition is well accepted today. Another definition that can be easily found is one that describes burr formation as "the result of plastic deformation". The metal that makes up the burr has, apparently, been transformed. We think that this explanation might answer an old question posed by Grepper in a thread entitled "Why are burrs so malleable?" We think the answer to that question might just be "because the steel that composes the burr has been transformed into a much more ductile form via plastic deformation."
We all know that when sharpening a knife that burr formation (plastic deformation) is the initial goal. So here is our first question; Is a HRC 62 edge more difficult to grind than a HRC 55 edge simply because it is offering more resistance to plastic deformation?
Here's the follow-up question that assumes you haven't developed serious disagreement with what we have proposed so far; Let's assume that we all would like to travel from point A to B. We elect to walk and you elect to ride your bicycle. We assume that you will arrive at point B before us and with less effort. But, in the end, we do all arrive at the same place. Could the same be said about edges whether they begin as HRC 62 or HRC 55?
We all know that when sharpening a knife that burr formation (plastic deformation) is the initial goal. So here is our first question; Is a HRC 62 edge more difficult to grind than a HRC 55 edge simply because it is offering more resistance to plastic deformation?
Here's the follow-up question that assumes you haven't developed serious disagreement with what we have proposed so far; Let's assume that we all would like to travel from point A to B. We elect to walk and you elect to ride your bicycle. We assume that you will arrive at point B before us and with less effort. But, in the end, we do all arrive at the same place. Could the same be said about edges whether they begin as HRC 62 or HRC 55?