K390: Brittle? Hard to sharpen?

[JuPaul]

Going through older threads on k390, and reading some about it in Larrin's work, it seems like k390 (and 10V) is often compared to a non-stainless s110v. So excellent edge retention, lower toughness. For those of you that have used it, do you find it chips easily (say, if you accidentally hit a rock or metal while cutting)? Also, the comparison to s110v makes me think it might be a real chore to sharpen. Thoughts on that from those of you that aren't expert sharpeners (just average sharpeners like me)?

People seem to love this steel, but if that love is mostly because of very high edge retention - at the cost of any decent toughness or sharpenability - then this may not be the steel for me.

[p_atrick]

I've never used nor sharpened K390, but this video by Deadbox Hero (Big Brown Bear on YT) shows all you really need to know about toughness:
https://youtu.be/E-c3LxQbcqg

[Mattysc42]

My pma11 mule sharpens as easily as s35vn or 20cv to me. No difficulty whatsoever, and much easier than s110v.

[Pancake]

Difficult? No.
Longer to sharpen? Yes.

I had some burr problems on my Police 4 and I was really doupting myself if I am worthy enough to sharpen K390. But problem was on my side and I was not hitting the apex properly. After that, it is quite easy to touch up and it really has an aggressive edge.
Can't really comment on toughness.

[aaronkb]

I've never used nor sharpened K390, but this video by Deadbox Hero (Big Brown Bear on YT) shows all you really need to know about toughness

The same video immediately came to mind when I opened this thread, lol

[koenigsegg]

K390 was pretty easy to sharpen on the Urban but that blade is really thin. Never had an issue though for almost a year carrying at 15dps cutting through thick plastic at work

[VashHash]

I know the mule performed really well for the me. Sharpened up easily with diamond stones. Got my P4 yesterday and after seeing that video I have no doubt it'll perform like the mule or better. I think i had cut a 4" or 6" x 20' polyester lifting strap into about 1" - 1-1/2" and it was still cutting paper. Wouldn't clean shave but with a light touch up it was shaving sharp again.
Excuse the old terrible quality pictures. These or a few years old

[JuPaul]

Wow, that video pretty much sold me. I don't "abuse" my folders, but I have been known to chip an edge accidentally hitting a rock or dropping a knife (I chipped my m390 para 3 just a tiny bit that way a few weeks ago). So the edge strength he talks about is what I'm after. Sounds like sharpening could be a long process, but on my KME should be doable with maybe a little learning curve.

[vivi]

I find it ery easy to sharpen for how wear resistant it is. No issues with it being brittle. I dropped the edge angle on mine and there has been no edge damage.

It's one of my top choices for a non-stainless. Very nice steel, I see why Sal likes it.

[Pelagic]

Super strong, stable (doesn't want to chip or roll), and very easy to sharpen considering it's 9% vanadium and 65 HRC.

[Larrin]

K390/10V/Vanadis 8 hav similar toughness to S35VN. So I wouldn’t call it brittle. Probably tough enough for most pocket knives.

[wrdwrght]

Neither brittle nor hard to sharpen. However, I haven’t let my Police4 or Urban become less than working-sharp. And I haven’t encountered a staple or a rock in my use.

[blendergasket]

Wow, that video pretty much sold me. I don't "abuse" my folders, but I have been known to chip an edge accidentally hitting a rock or dropping a knife (I chipped my m390 para 3 just a tiny bit that way a few weeks ago). So the edge strength he talks about is what I'm after. Sounds like sharpening could be a long process, but on my KME should be doable with maybe a little learning curve.

I sharpen my K390 Urban on my KME and it works great. It takes a little longer than a less wear resistant steel but if you're patient it takes an excellent edge.

[Cambertree]

Jupaul, I’ve used the K390 releases a fair bit.

I took the Edgematters Pingo (along with a GEC Crownlifter) to Ireland as my travel knife. I lost that knife when I got to Malaysia and my suitcase arrived busted open, with the Pingo missing. The airline paid for a replacement, and as I had no more need of a two-hand opener, I got the K390 Urban instead.

I used the K390 Urban as a work knife in a warehouse type environment for about a year. It never chipped when hitting the occasional staple or steel rack. When I lost it one day at work, I replaced it (at BBS prices :eek: ).

I use the Police 4 a fair bit as a folding utility kitchen knife.

So having said all that I think it has excellent relative toughness and sharpenability for a high wear resistance steel.

I’ve never had chipping or microfracture issues with it. I’d still describe it as a pleasure to sharpen, and it rewards you with a superb fine edge. It also seems to be one of those steels which does very well with both coarse and refined edges.

It does take a patina very readily, and therefore mandates a bit of preventative care.

It’s probably my outright favourite bladesteel so far.

[ZrowsN1s]

...... Sounds like sharpening could be a long process, but on my KME should be doable with maybe a little learning curve.

Diamonds. And a lot of patients. Good news is once you get it sharp it tends to stay that way a while.