08-11-2018, 10:10 AM
Isn't this interesting stuff? We first noticed the phenomena back when the frame of the prototype KN100 used to look like this as opposed to this.
Knives left in the test apparatus that had tested 200 in the evening tested 30 - 60 points higher in the morning. We attributed the change to what we referred to as "metal memory" and/or oxidation. We know that an uncoated, brand new razor blade left out of it's wrapper overnight will measure 10-15 points higher the next morning. We attribute that change to oxidation. We've coated knife edges with oil and left them out overnight and they still deteriorate in sharpness. We called that "metal memory". We did a little research on the subject just a few minutes ago and have to agree that "metal memory" may not be the most correct engineering term for what we seem to be witnessing here. Perhaps "relaxation" is a more appropriate term. We do sense with the problem that elements of the edge emerged from the grinding process in a particular orientation and that they seem to be trying to get back to where they came from. Perhaps that's all just balderdash and someday we'll learn that it is all due to oxidation or some other "yet to be discovered" phenomena but that's where we are for the time being.
We do know that it is an issue for our BESS Partners (the people who attach BESS numbers to sharpened products). They leave the BESS Partner's factory at 200 and arrive at the customer's location at 240. Always higher and never lower. As always, a little stropping or similar exercise and the edge returns to it's original sharpness level. Just like so many other things that we have discovered about edges through sharpness testing, this just seems to be how it is in the world of edges and as KG suggests "We know that the edge sharpness will worsen after sharpening, and we know it is due to something happening in the very apex. We also know how to fix it when it happens."
Thanks to Grepper for uncovering and then disclosing his findings. In our opinion, this kind of work is one of the real values of edge sharpness testing. In all this though Ken turns out to be, as usual, the most percipient. He is the first to decipher the subliminal message buried in the Edge On Up company name...never store your knives edge down, always edge up.
Knives left in the test apparatus that had tested 200 in the evening tested 30 - 60 points higher in the morning. We attributed the change to what we referred to as "metal memory" and/or oxidation. We know that an uncoated, brand new razor blade left out of it's wrapper overnight will measure 10-15 points higher the next morning. We attribute that change to oxidation. We've coated knife edges with oil and left them out overnight and they still deteriorate in sharpness. We called that "metal memory". We did a little research on the subject just a few minutes ago and have to agree that "metal memory" may not be the most correct engineering term for what we seem to be witnessing here. Perhaps "relaxation" is a more appropriate term. We do sense with the problem that elements of the edge emerged from the grinding process in a particular orientation and that they seem to be trying to get back to where they came from. Perhaps that's all just balderdash and someday we'll learn that it is all due to oxidation or some other "yet to be discovered" phenomena but that's where we are for the time being.
We do know that it is an issue for our BESS Partners (the people who attach BESS numbers to sharpened products). They leave the BESS Partner's factory at 200 and arrive at the customer's location at 240. Always higher and never lower. As always, a little stropping or similar exercise and the edge returns to it's original sharpness level. Just like so many other things that we have discovered about edges through sharpness testing, this just seems to be how it is in the world of edges and as KG suggests "We know that the edge sharpness will worsen after sharpening, and we know it is due to something happening in the very apex. We also know how to fix it when it happens."
Thanks to Grepper for uncovering and then disclosing his findings. In our opinion, this kind of work is one of the real values of edge sharpness testing. In all this though Ken turns out to be, as usual, the most percipient. He is the first to decipher the subliminal message buried in the Edge On Up company name...never store your knives edge down, always edge up.