RC Value on Military -- Help!

[Guyon]

I've been psyching myself up to get this knife for about a week. After seemingly endless research and several hours pouring over posts here on Bladeforums, I've finally navigated the big questions that any buyer of the Military must face--serrated vs. plain, old model vs. new model, ATS-34 steel vs. 440V steel.

I've finally decided on a plain edged, 440V steel Military in the newer model.

My last question here concerns the RC value. I've read in a couple of posts that Spyderco lowered the RC value of the 440V steel from the high 50s to the mid-50s to increase durability.

My question is this: How do I know whether I'm getting the 440V steel in the mid-50s range?

My next questions are: Should I even be worried about the RC value? Is it that big a difference as far as potential chipping? Are there even any of the upper-50s knives out there?

Someone help so I can finally order this knife and get some peace of mind. I'm tired of doing my homework.



[This message has been edited by Guyon (edited 03-21-2000).]

 

[Dmitry]

Hardness of Military 440V blade is ~57RC.
It's nearly perfect match for given blade shape and sizes. Blade is "wedge-shaped" in two dimensions: it narrows from handle to tip and from back to the edge. Main advantage is that such a blade will cut like crazy and penetrate with slightest touch, outperforming most of other folders. It will not just partly plunge into the target, it will go all in it with minimum resistance.
But on the other side blade with such a geometry will be fragile if made of high HRC steel (HRC ~60-62).
HRC 57 is nearly ideal for combat knife cause if it meets some obstacle, say bone, blade wouldn't break or dent.
Also CPM440V steel couldn't be hardened more than ~58HRC.

 

[cerulean]

It's my understanding that all of the new Military models on the market now have a RC hardness in the mid 50s. I'm not sure if you can buy one in the upper 50s anymore. I don't think there is any easy way to determine the hardness of the blade, except to do an RC test, of course.

Does it matter what the hardness is? Probably not much. Spyderco wouldn't have made the blades softer without a reason though, so there probably was a potential for chipping at a higher RC. I've heard of some incidents of 440-V chipping at a high RC, but I don't think it was that common of a problem.

I believe that my Military is at the lower RC. I can't back that up with an actual RC test, but it feels soft when I sharpen it. I've done a few very unscientific tests on it by flexing the edge against a brass rod and it seems that the 440-V in the mid 50s is as tough as ATS-34 in the low 60's.

I'm sure that ATS-34 would be tougher than 440-V at the same RC, but remember that you're trading off for wear resistance. Wear resistance for 440-V is waaay better than ATS-34. I mentioned that I've sharpened my Military a couple of times, but it really hasn't needed any sharpening.

Anyways, RC values aren't that big of deal and you probably shouldn't worry about that stuff too much. It would be nice to find a "perfect" steel and a perfect RC for it, but I doubt we'll ever do that.