edge performance: expectations

ScottRoush

ScottRoush

Joined
Jan 10, 2010
Messages
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I've been playing around with stock removal on 0.095 15n20 making bushcrafters and other hard using type knives. So I've started upping my ante on testing because I want to provide bushcrafters and survivalists with the best edge I can produce. So I recently made a big chopper with the 15n20 and did a little test where I did some hard cutting on a frozen red oak knot (it was 10 degrees out :eek:)... and it still cut paper as well as before the cutting.. and I really gave it man... almost 2 minutes of wood removal on wood as hard as nails. The 15n20 was tempered at 400.. not sure what that Rockwells to. I'm using a convex edge that is very thin.. thinner than any camp chopper I've ever used. I was impressed with how it handled that red oak.. although I suppose there are better evaluations than slicing paper.

but today I tried another blade.. heat treated the same, same edge grind.. but this time I did a lot of batoning.. splitting and hacking into that same gnarly piece of frozen oak. This time it wanted to tear the paper a bit... it still cut, but not as efficiently..and it didn't cut my rope at all (before it was slicing it easy as pie).

So... was the batoning on such hard wood just too much for any blade or steel? I mean.. It didn't fail or anything... no crumpling, nicks, cracks, roll overs, etc. It just got a bit dull.

Anyway.. my point here is this... what should be my expectations after almost a solid 2 minutes of vicious chopping on very hard wood? One thing that occurred to me here... when I did the first test I hand chopped.. which, I think, distributed the wear to many parts of the blade. But the batoning concentrated it to just the middle area of the blade.. which is where it got dull.

So... again... what should I expect if my 15n20 was heat treated perfectly? Am I asking too much?
 
I do quite a bit of testing but try to stay with tests that can be reproduced and reflect the use of the knife. Before starting the test it is best to have and idea of what a good outcome would be and then see how the knife performs. Batoning frozen wood has alot of variables which you cannot control, my question would be, did the knife meet expectations? Shaving with a knife used for batoning frozen oak may not be a resonable expectation. If someone were forced into a survival situation and depended on your knife would it do the job, seems like it would.
 
It seems to me that your tests show the 15N20 is a good or better than CPM154 or other similar steels. It just doesn't seem reasonable. I'm sorry but I had to say that. Frank
 
Design your knife based on what you want to cut with it.

I'm not being a smarty-pants, that's honestly the best advice I know.
 
I agree with James. If a knife is for bushcraft use, chop down some small trees.....make some tent stakes....make a spear.....cut up a deer or two....then slice up a slab of bacon and and a tomato or two. That should let you see if the edge is damaged or getting dull. The ability to cut paper won't normally be a bushcraft task.
 
I'm more interested in your heat treat method.

15N20 is basically 1075 with 2% nickle, I believe.

1075 can make a pretty good knife. I don't see any reason why it couldn't hold up to these tests, if properly heat treated. There are so many variables in testing... you could repeat the test and probably end up with different results. I would say the baton definitely placed the edge under more stress. Stacy and mr T have it right... you make bushcraft knives? Test them with bushcraft uses in mind.


Rick
 
J
Frank Niro said:
It seems to me that your tests show the 15N20 is a good or better than CPM154 or other similar steels. It just doesn't seem reasonable. I'm sorry but I had to say that. Frank
Click to expand...
Good is a relative term, those are tasks for which 15N20 is exceptionally well suited. CPM 154 is not designed for that type of abuse, so it may be that in this particular application, 15N20 is the superior steel. On the other hand, I have done a lot of comparisons, and for the kitchen knives I just started, CPM 154 is the ideal choice

-Page
 
Expectations and destruction/failure are two different things in my view.

I do ocassionally test thin sharp bushcraft-worthy blades to complete failure, because it's fun and gives me confidence that they will exceed my expectations. For instance, I recently beat the dickens out of a thin, acute CPM-154 blade and was frankly surprised how much it took to dull it and I never did snap the tip. However, it wasn't designed to chop and dig through 2x4's and I tell potential clients "I do that so you don't have to!"

Edge geometry for the expected tasks should be considered first. The choice of alloy and heat-treatment can be built around that. Just thinking out loud, as usual.

P.S. "mrT"... that's funny... I haven't had a mohawk in a couple decades ;)
 
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