Dendritic Cobalt in a Liner Lock?

James Mattis · Oct 29, 1999

One of Spyderco's "works in progress" is the testing of a few Militaries with Dendritic Cobalt blades. David Boye makes some interesting lightweight lockbacks in Dendritic Cobalt. Their claim to fame is a very aggressive, very long-lasting edge from a network of hard carbide crystals in a soft matrix, so that the blade has a Rockwell hardness a lot softer than a steel knife blade.

My question is, how would the "low rockwell" tang of a dendritic cobalt blade perform engaging a steel or titanium liner lock spring? Would it create new liner lock design variables?

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- JKM
www.chaicutlery.com
AKTI Member # SA00001

Dirk · Oct 29, 1999

Isn't titanium normally a low Rockwell hardness? Also, if the engaging surfaces were kept smooth, would that also help the difference in hardness?

I know there is a lot to this, but it still amazes me that you can have a metal that is easy to sharpen, but holds an edge forever (cobalt). Then you have a metal that eats up machine tools, belts, saws and grinders, but it won't hold an edge for very long (titanium).

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Paranoia is only smart thinking
when everyone is out to get you.

Outlaw_Dogboy · Nov 2, 1999

This thread makes me wonder about how I would like the dendritic cobalt, or talonite, for that matter. From what I hear, in both instances, you have excellent edge holding in a blade that Rockwell's fairly (or even VERY) soft. It seems to me that in that case, you would get a lot of edge rolling if you encountered anything ... hard (?)... such as.... oh... well... my infamous (now) staple test.

Yeah, it will hold an edge forever if all you're cutting is paper, cardboard, wood, flesh (things that try to dull in the micro-scopic). But, if you hit something that tries to dull in the macro, like the staple, your edge just went down the tubes.

Anyway, just thinking out loud... Anyone actually done anything like this with the talonite, or the dendritic cobalt?

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...when it absolutely, positively has to be cut right now...
Outlaw_Dogboy

Longden · Nov 2, 1999

OD, they'll have to name that test after you!

Then, a blade steel that goes down in flames on the test can be said to have "OD'ed"

Outlaw_Dogboy · Nov 2, 1999

Hey, I like that!

I sent my BF Native back to Spyderco, so's Sal could take a look at it. Man, I miss that knife already, and it's only been gone a few days. I don't care if it was soft (the steel, that is), it was/is a NICE knife.

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It's just a ***king staple!
Outlaw_Dogboy

storyville · Nov 3, 1999

Just my .02 --

Rob Simonich noted in a prior thread that, in his tests, talonite chews thru knots in wood w/o any discernible wear. Folks who have used them in a variety of circumstances indicate that it retains its edge after hitting bone and other hard materials.

How so? I dunno -- you'd need to inquire w/the more scientific-minded on this forum. I also don't know how this would translate into the cast stellite which David Boye uses... will be interesting to see Spyderco's testing results, when they get to them.

Steve B. · Nov 3, 1999

I`ve been carrying a Boye folder for a few months now and using it daily at work. It does a wonderful job on slicing tasks, such as cardboard and plastic.

I had heard reports that dendritic steel was chippy. I`ve found that to be true. The other day I was cutting down some cello strings. I`ve done this before with my BF Native (440v) without any apparent wear. I tried it with my Boye and I chipped a tiny little piece off the edge.

I believe that the brittleness of Dentritic steel has been acknowledged by it`s users for some time now. If this is true, I feel that the Military is exactly the wrong pattern to be using this steel. I think it would be more appropriate in a Jess Horn type of pattern. It makes a nice gentleman`s (or ladies!) folder, but I wouldn`t use it for a hardcore, survival type of user/abuser knife. I certainly wouldn`t want to chop through a bone with this steel!

I still think it`s a fantastic material in the edge holding dept. Rivals 440v!

Just my .02.......

James Mattis · Nov 3, 1999

Maybe, for high performance on opening mail and slicing bagels, the C25 Centofante would be a good pattern to do in Dendritic Cobalt.

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- JKM
www.chaicutlery.com
AKTI Member # SA00001

JoHnYKwSt · Nov 3, 1999

OD,

I dont have any experience with talonite but it will roll and dent more then steel. That is why knives that are made with it have a thicker edge, to compensate for the softness of the material. It'll probably still cut better than a steel blade that has had the edge roll or dent because it is more slippery than steel.

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Johnny
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Outlaw_Dogboy · Nov 3, 1999

Thanks Johnny. That's pretty much what I suspected.

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It's just a ****ing staple!
Outlaw_Dogboy

Samurai6 · Nov 3, 1999

Actually, the Military might be just the platform for BDC. Talonite specifically seems to work very well with combat type edges. Keep the edge fairly thick, and sharpen it at around 40 to 45 degrees included, and you have a pretty durable edge that won't chip on non-metalic materials, and will be strong enough for pretty hard use.

I can't see the advantage of BDC over CPM440V in a knife like the Military though, unless you were in damp, corrosive environments, day in and day out. CPM 440V should hold an edge almost as long and be more durable, allowing a finer, more aggressive, more efficient, cutting edge.

Oh, and about liner lock wear: I remember reading on Rob Simonich's site that Talonite has a smooth crystal structure, so maybe it wouldn't wear on a Ti lock bar as much as a steel blade would. But, a dim memory from college tells me that how two materials wear depends on their relative crystal structures, kind of a like structures wear, dissimilar structures don't kinda' thing.

[This message has been edited by Steve Harvey (edited 03 November 1999).]

Sal Glesser · Nov 4, 1999

James - At this time, we have no plans to "produce" (production) a Military cobalt version, only to test the material in real life studies. The Military model is a "test" platform or what we call our "lab rat" for an "all around" (no rules or laws) "get the job done" reliable folder. The same goes for the smaller version...just a test.

For me, this forum represents a certain amount of R & D Research that seems to be carried out with fewer than 100 aficianados of the art. Too many to communicate on a daily level with all. Sharing R & D thoughts provides knowledgable opinions about "what will work".

"What will sell" is tested by our highly skilled Sales & Marketing people.

However, we won't try to sell it if it doesn't work well.

The Military "cockpit" area is highly refined and a good platform for testing any folding knife feature.

sal