+
I had one when they first came out, it was stolen and I recently got this one as a gift. The edge has been sharpened, looks like it was burnished, possibly from a carbide scraper, it reflected light and would barely slice photocopy paper :
The edge is 0.018" thick and ground at between 15 and 20 dps, it isn't perfectly even. As this is likely the first time this knife had the edge bevel ground I was going to have to do some serious metal removal to even out the bevels. I used a 300 grit Suehiro Ryu stone which is a pretty fancy dual-density stone :
I used the soft side of the stone and 1/2 lbs of force (pressure was between 10 and 20 psi). This formed a very light slurry as it was just past the LCP of the stone, but well under the UCP. The stone cut well and quickly started evening out the edge bevel. After just 50 pps the edge would no long show any marker left on the edge, however the apex was not fully formed, still reflected light.
This is AUS-6 (same class as 12C27) which is a very nice cutlery steel. Unfortunately it gets used in the cheap knives a lot so it has a poor reputation but on a property level it is a stainless equivalent to 52100 (can reach ~60 HRC and has a very small amount, < 5% of chromium carbides). It is easy to grind, however since I was using a very low force and thus a small pressure it still took another 250 pps before the apex didn't reflect light :
This is the current method of sharpening I am experimenting with, which was prompted by a discussion I had with Chum a few months ago. I would consider it advanced sharpening and would not in general advocate it over the normal 3-step method, but it has some advantages if you are willing to use a bit more technique.
The goal is to stop after the light stops reflecting from the apex, but before the apex fully forms. This may sound difficult, but it really isn't. I just checked the apex after every 50 pps which takes just a few second.
The apex is thus not over ground at all and left with a small flat (< 10 microns wide). The knife has the ability to slice newsprint ok, scrape shaves but won't push cut newsprint or catch hair above the skin. However it is extremely durable for very heavy work as it hasn't actually formed a true zero-apex. That small flat on the edge leaves is very durable for really heavy work like cutting sods.
However even if you don't want that high durability there is also another reason to sharpen in this manner which is that is the perfect edge bevel to use to set the apex bevel, the main reason I do it. In this case I used a MXF DMT, a Spyderco Medium benchstone is another nice choice, which gives a high push cutting ability and still a decent amount of edge retention on a slice :
That tiny apex bevel, was formed after just 5 pps on the MXF DMT. This produces a very high sharpness, cuts hair above the skin, push cuts newsprint, etc. but for heavy work like the sod cutting will take damage more readily.
Note there was no burr formation during any of this grinding so there is no burr removal used. As there is no over grinding there is zero wastage of steel, sharpening removed no material from the width of the knife. Those are two other reasons that this style of sharpening is becoming my regular method.
