How bad / dangerous is this?

[Obsessed with Edges]

How the hell do you crack a blade opening a can.

Brittle, brittle steel at very high hardness. Any lateral stress on the blade can do it, with that steel (ZDP-189, apparently). Almost like doing it with a blade made of glass. ZDP wasn't made for prying or any other such tasks. All the emphasis is on edge retention, when the knife is used purely as a cutting tool.


David

 

[Odin's Son]

What is that wavy line?

Edit: Forget it, I found a picture of it.

 

[Razorsharp-Travis]

you dont pry cans open is what im implying. id expect chips at most

 

[mr_anderson]

Yeah, they will replace the blade for $10, do that and and don't open cans with it anymore.

 

[Mack]

Never mind.

 

[Obsessed with Edges]

you dont pry cans open is what im implying. id expect chips at most

The crack probably started as a chip at the edge, and then propagated from there with a little lateral stress on the blade. Sort of like a crack on a car's windshield that starts with an impact chip from a pebble, and just keeps growing with each little bit of twist & flex of the glass.


David

 

[Noctis3880]

Yeah, they will replace the blade for $10, do that and and don't open cans with it anymore.

You sure about that? It's a limited run IIRC.

 

[fsatsil]

Best way to find out is to contact Kershaw. I'd be surprised if they had replacement blades for limited runs or long discontinued knives but you never know.

 

[Obsessed with Edges]

This blade is essentially ruined anyway, in terms of full functionality. Only a matter of time before a big chunk of it fractures out*, if the knife gets used much at all. Even if Kershaw can't replace it with the same limited-run blade, pretty much anything they do use would be a step up from where it is now.

* = In the OP's first pic, it almost looks like there's another thin crack developing below the first one, though it looks as if it hasn't yet gone all the way through the blade yet. Can't see it in the 2nd pic, looking at the other side. If it is a crack, I could see that whole section between the two cracks breaking out, eventually.


David

 

[rnbtexas]

This blade is essentially ruined anyway, in terms of full * = In the OP's first pic, it almost looks like there's another thin crack developing below the first one, though it looks as if it hasn't yet gone all the way through the blade yet. Can't see it in the 2nd pic, looking at the other side. If it is a crack, I could see that whole section between the two cracks breaking out, eventually.


David

I agree, it is rotated top to bottom and not edge to spine. You can just barely see it at the braise line. About to have a chunk out of the blade.

 

[KennyB]

Would this blade have snapped cleanly if it was totally ZDP-189?

 

[Obsessed with Edges]

Would this blade have snapped cleanly if it was totally ZDP-189?

With those cracks, I'd bet it would. In the pics, you can see how the crack is stopped cold or interrupted at the joint between the two steels. I think the other steel in this one is Sandvik (something like 14c28N, maybe), and I'm sure it's tougher, from the standpoint of preventing a complete break. That's essentially the idea behind these composite blades anyway, to give the super-hard/brittle steel at the cutting edge a stronger/tougher backbone. Still not bulletproof, obviously. With ZDP, I sort of view such a config as tempting fate, in making the user think the blade as a whole will be stronger/tougher than it actually is.

After snapping the tip on a ZDP blade of mine, I don't have any faith in ZDP's ability to absorb much lateral stress at all. When mine broke, it felt just like snapping the tip off a freshly-sharpened pencil; it was that easy, even sounded the same.


David

 

[wilejoe]

To the OP, I agree with the idea of you though in sending in the knife, for two reasons. First, you have nothing to lose. It is a broken tool, and broken tools are dangerous, especially those that cut. To me (recognizing I don't have the finely hones skills of monitor perception that tells the actual condition of a tool) the brazed cover/sandwich is all that is holding that blade together. Not good. Otherwise, that knife looks a little chewed up to me, but the cries of abuse probably come from the fact that many here are light users or collectors. Aside from the crack, there is plenty of steel to sharpen out those chips.

Second, Kershaw is run by a group of adults, all of them full grown at this time. They have a reputation for great customer service. But... they can also say no. If they decide you have used the knife for something that is well past their design intentions, (if they follow their past behavior) they will fix it for a fee or send it back. Let them make the decision. Heck, they may fix it just so that you will come back here and brag on them to get another couple of hundred knife sales in the future when the repaired knife comes back and you let everyone one know that they "took care of you".

I mean, after all, rereading your post, it wasn't like you were expecting something for free...

Robert

+1 I agree it's dangerous

 

[KennyB]

With those cracks, I'd bet it would. In the pics, you can see how the crack is stopped cold or interrupted at the joint between the two steels. I think the other steel in this one is Sandvik (something like 14c28N, maybe), and I'm sure it's tougher, from the standpoint of preventing a complete break. That's essentially the idea behind these composite blades anyway, to give the super-hard/brittle steel at the cutting edge a stronger/tougher backbone. Still not bulletproof, obviously. With ZDP, I sort of view such a config as tempting fate, in making the user think the blade as a whole will be stronger/tougher than it actually is.

After snapping the tip on a ZDP blade of mine, I don't have any faith in ZDP's ability to absorb much lateral stress at all. When mine broke, it felt just like snapping the tip off a freshly-sharpened pencil; it was that easy, even sounded the same.


David

Yeah, that's basically what I was considering. I like the composite blade concept from Kershaw, and this is the first time I've seen it work in a way as intended. If that blade were totally ZDP then it would have broke cleanly. It's still a failure, but one that allowed the user to complete the job and send it away for warrany repair. And as others have mentioned, if it's a factory default they will replace for free, and if not then it's only $10 for a blade replacement.

I think this is actually a really good advertisement for this composite blade material. Wish i coud get in on some of this ZDP-189/14C28N run