View Full Version : Lets talk edges II


C L Wilkins
10-23-2002, 06:08 AM
Earlier this year, Ken Ragnoor started a post entitled, "Lets talk edges", which was pretty interesting. I mentioned a 440V blade that I had made, it was just a 3 1/2 inch drop point hunter and I dressed a number of deer with it. The original post can be found here (http://www.ckdforums.com/showthread.php?s=&threadid=4379&perpage=15&pagenumber=2) .

As a followup and an update to the post...

I wrote the following in that post...

I was really pleased that no chipping whatsover occurred on the edge with this 440V blade as I have heard some other makers complain of in the past. I contemplated this and when the blade was hollow ground, I left the edge a little thicker than normal. It is not a paper thin edge by any means but thin enough to do the job. This was not the first 440V blade that I have made but it is just the first one that I decided to personally put through the paces.

I was resharpening the blade last night and cannot prevent the edge from chipping, particularly in one area. One wrinkle to this story is that the blade was left in a case and had gotten wet. There was a bit of corrosion on the edge. I was cleaning it up last night and attempting to put a polished edge on it.

I had no inclination to use this steel in the future but that is a "definite" now.


Craig

Fox Creek
10-23-2002, 12:17 PM
how hard is this blade that is chipping? I wonder if maybe it might perform well just a tad softer.

C L Wilkins
10-26-2002, 09:41 AM
That is what I suspect, it is too hard. If it were carbon I would have drawn it back some more after checking it. I guess this will stay "my knife". I think I will have it checked just out of curiosity.

A little advice...don't ever even think about even giving away an inferior blade. It will come back to haunt you! If it isn't up to your best, buff or grind your name off of it and only use it in the shop or deep six it! I heard a horror story of a maker that ended up paying $500 to get his own knife back!

Craig

Jerry Hossom
10-26-2002, 11:21 AM
What Crucible has learned after some years of experience with CPM steels is that the ultra high carbide capability (>2% carbon) is not really demonstrating the ultra high wear capabilities they looked for in many applications. For example they've learned that CPM-3V is outperforming CPM-10V in stamping dies and some other applications, due to the tendancy of the very high Vanadium/high Carbon alloys to chip easily. S60V(440V) shouldn't be hardened above Rc56 or its capacity to withstand impacts drops dramatically. What often happens to these steels (an I suspect many others) in knife blades is microchipping. The problem manifests itself by a blade being very sharp and remaining so for a little while, then it goes completely dull in a hurry. This is especially noticeable in very fine edges. If you look at those edges under magnification you'll see they are very ragged.

I think you'll find that S30V ultimately replaces both S60V and S90V(420V) in the Crucible inventory. In practical use it outperforms both. in 2001, CPM-3V was their largest selling knife steel, outselling even 154CM.