Sharpness of the Military

Dannyc

Dannyc

Joined
Feb 20, 1999
Messages
1,284
I recently bought a Spyderco Military, and knowing that it's made of 440V premium steel, I had no qualms about it cutting aggressively.

Imagine my surprise when I tried cutting just one high-tension wire for my car. The wire has no metal cords in it, just nylon and rubber stuffs. Yet, after cutting just one of those, the edge on my Military turned blunt.
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By blunt, I mean not only could it not shave hair, but I can't even cut newspaper without the edge snagging and tearing the paper up.

After sharpening it manually with my Spyderco Profiler, I got a good edge back. But will it last?

I would like to hear others who owns a Military, and how long the edge lasted in between sharpenings.

Dan
 
Why not try to cut the same wires again and see how it holds up this time? BTW, the 'rubber stuff' should be some sort of graphite or carbon...

I have NEVER had any problems with either of my Militaries (one serrated and one plain). I also tend to use quite an acute sharpening angle (for that EXTRA bit of sharpness
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). The things I cut can not be grouped into just a simple class, because I 'abuse' both knives on a regular basis. I recently had to cut through an electric wire the size of my thumb, without loosing too much blade performance. I am not trying to say the Military did not feel it, just that ANY other knife would have been USELESS after performing this feat! (It was the serrated Military on this occasion...
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)

Up the MILITARY!!!
 
Dannyc, it should retain its edge much better than that. It is a steel knife after all. Even AUS-8 will perform at a much higher level than what you describe. I can use my Calypso in the lab to cut through 1/2" cable that contains 3 multi-line copper wires and the edge will suffer no impaction. The trick is of course to keep the cut smooth and straight.

Maybe the Military had a bad edge to begin with. There could have been a wire edge left on it for example. Like has been suggested, resharpen and try some more cutting. It should easily be able to handle extended cutting on rubber / plastics / ropes and the like.

-Cliff
 
Yes, I believe it should have performed more than that. That was why I was surprised when it only cut one high-tension wire which has no metal content whatsoever, and yet that was all it could cut, before it went blunt.
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The edge was still a factory edge, Cliff. And it was very sharp back then, slicing paper was a breeze. The way I cut the wire was to fold the wire into a loop, then slice it in-between and outwards with the Military.

I will try my M2 AFCK later, and see what happens. This is really strange, as I've heard that the 440V shouldn't act that way.

Heyns, electric wires? Gee.. I also heard it can do that, though after cutting through these wires that I have (which doesn't contain metal) and not being able to even cut paper afterwards, means something is wrong.

Dan
 
Dan,
boy, was I surprised at the performance of the serrated Military! I was in a bit of a spot, being alone in the styx during a field trial and needing to make modifications to the electrical supply without a sidecutter in sight... Well, MILITARY to the rescue!!!!
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Being a 3-phase supply of 120A rating, I had to cut through 3 conductors, each the size of my thumb in diameter (about 1.5 cm diameter). The BEST is that it took less than 2 minutes to get the blade back in shape using the MF204 Spyderco Sharpmaker (full sharpness restored - ALL SYSTEMS GO!
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)!!
 
Heyns, you sure got one nasty cutter there.
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Hmmm.. maybe it's the edge. Maybe I should've gotten a fully-serrated version instead, if I mean to cut up stuffs found in auto restoration shops (you're right, graphite and carbon compound rubber hi-ten wires).

Sigh.. oh well.. I guess this one's good enough for more meager tasks like cutting steak or something, hehehe...

Dan
 
Dan, the direct comparasion to the M2 blade is an excellent idea. I would be surprised if the 440V is significantly lower in performance. I would expect it to be a fair bit higher.

-Cliff
 
Cliff - Our tests indicate CPM-440V to superior in edge retention to M2 by an average of more than 40%.
sal
 
Cliff, I'll try to test out the M2-AFCK and cut the very same wire to see if edge retention would be any better or worse. Since I've already done that with the Military, we'll see how the AFCK will fare against that rubberized wire.
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Sal, 40%? Hmmm.. let's see what happens after I test it.
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Dan
 
Cliff, just came back from the motor shop, and I did some tests on the cutting ability of both the Military and the AFCK-M2.

Using an 8mm. hi-temp silicon graphite hi-tension wire as a test object for cutting up, here's what happened:

Straight cut downwards:

AFCK in M2 steel cut through cleanly, and is still shaving sharp.

Military cut through cleanly, but couldn't shave anymore.

I then proceeded to cut through magazine paper, to see if edge was retained on the Military, and same as yesterday, it did cut but was tearing through the paper. The AFCK cut cleanly though the magazine paper without any problems.

I even tried cutting through the high-tension wire (free-hanging) and the AFCK-M2 was able to cut through with one swipe. The Military bounced the free-hanging wire around, and was able to cut about 1/2 of the wire, but not completely.

I continued cutting through the high-tension wire using the AFCK (straight cut, no sawing motion) and ran out of wire to cut, but the AFCK could still shave hair, but it already bites, and is not hair-popping anymore.

The Military can still do straight-cuts but just glides through hair, and doesn't bite at all.

I dunno if it's the grind or the steel, but I'm rather surprised that the AFCK won over the Military in edge retention.

Oh yeah, the Black-Ti coating on my AFCK didn't suffer any scratches (since it's silicon-graphite rubber I'm cutting). The edge on the AFCK is factory edge. I just resharpened it right now.

If there's any other materials that you people can suggest for me to test, I'd be glad to do it again, as I can't understand why the Military isn't cutting like it's supposed to, considering it's flat-ground compared to the saber grind of the AFCK.

Dan
 
Dan - Doesn't sound right. I would guess heat treat is off. Ought to send it back to us.

Our M2 tests were done with an AFCK. Factory edge was 50 degrees and wouldn't cut well. We resharpened and got good results, but not to compare to 440V. I'd like to Rc the blade at the factory.
sal

 
Hi Sal!

Err... that would be impossible for me right now, as I'm in a rather tight spot, can't afford to ship anything. And shipping from here would cost me about as much as a Wegner.
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Our M2 tests were done with an AFCK. Factory edge was 50 degrees and wouldn't cut well. We resharpened and got good results, but not to compare to 440V. I'd like to Rc the blade at the factory.
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50 degrees? That's 25-degrees on each side, right? Hmmm.. I don't think my AFCK has that angle on the edge. I'd say it's around 20 degrees on mine. That's factory edge. Though not sure, as I sharpen my blades manually, even if I have the Sharpmaker.

I wonder if there's something in the silicon hi-tension wire that doesn't jive with the Military. But I doubt it, coz considering the edge angle of the Military, and the grind, it should by all intents and purposes, outcut the AFCK, right? I thought thinner would be better. Maybe it's thin, that's why it didn't retain its edge. I'm still thinking what stuff I can cut here for testing. By now, I have already resharpened both knives, but retained their angle still, so it's as close to factory edge as possible.

If it's the heat treatment, is there any test I can perform to find out for sure? and what results to expect?

Sal, what materials did you cut for the test?

Dan

 
I'll wait for my BF Native to arrive. Since it's also in 440V, maybe that would be a good comparison for the Military and the AFCK.

If the Native cuts as well as it should, then there might be something wrong with the Military as you said, Sal. I'll only be able to find out once the Native arrives.

Dan
 
Dan - My guess would be the blade is not at proper heat treat. There shouldn't be any particular material that would affect the steel. I've used my Military on stuff you shouldn't try to cut and still found performance exceptional. I've chopped hard dry wood with serratd versions, even sheets of sandpaper (probably one of the worst). Never experienced what you are describing.

In our testing, we cut a special card stock that is scientifically formulated to have a certain content of abrasive, wood stock, etc. It was calibrated to provide a realistic test with 200 to 400 cuts. The material is purpose built in a French paper factory to meet specs. Pressure is maintained at a constant level and the CP measures and graphs and stores the cuts. measures initial performance (sharpness) and edge retention.

It has proven to be the most accurate method we have been able to build or buy. We've been testing edge retention for about 10 years, one way or another.

It order to determine the problem with the blade, we would have to have the blade in our lab. Perhaps Danelle can retrieve the pc & replace it with one that we Rc before sending?
sal
 
Hi Sal!

Hmmm.. I guess I won't be able to test it with those things you mentioned.
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I can only test it in the real world with things that are available to me at that time. As I've never cut anything with it except paper and lately, the high-tension wire, I was still able to put a sharp edge on it again. It takes a good edge easily, which is why I'm wondering how come it loses it so fast.

Anyway, if I'm going to ship this back to your company, I'd have to do it using UPS, right? I'll have to check how much they are charging to have this shipped first.

I initially bought this for display purposes only, Sal, so it's really not a bother if it could retain the edge or not, or if the RC is wrong. If the latter is true, then I guess it will remain as a display piece for me. I'll check with the shipping first, then let you know okay?

For what it's worth, I still believe this knife is one of the best I'll own.
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Dan
 
Reading this I couldn't help thinking of that very first pre-production Military in 440V that went to Tactical Knives for a review. For some reason they didn't know it wasn't treated at all and were, um, surprised by the poor edge-holding. They (and the rest of us) have seen substantially better performance from treated Militraies, of course. Sure was funny, though... especially the way, being a knife mag, they had to really tiptoe around saying anything especially negative about the knife
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------------------
-Drew Gleason
Little Bear Knives
 
Hmmm... I don't really know if this was one of those early 440V models, but since I bought it here at a local store in the Philippines, where knives that cost this much doesn't have a strong following, this might be an old stock or something, and might have also come from the same batch that had bad RC treatment.

I can't really say, but the edge doesn't hold out for long on my knife. I was just wondering maybe it wasn't meant to cut some things, which I did.
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Oh well, since I'm very much into racing cars, it'll be more than just hi-tension wires that I'll be cutting, and since there'll be an upcoming rally event here, I would surely love to have a knife beside me that can do emergency cuts, and not dull right away. Maybe I need a chainsaw.. hehe!

Dan
 
Sal, the 40% doesn't surprise me as CPM quotes very high wear resistance for 440V well over M2. How hard was the M2 you tested against?

Danny, the results of the M2 are inline with what I have seen on a well used mini-afck. I lowered the angle on mine and it still had very good edge retention. It could for example easily make vertical slices though pop cans without edge deformation (providing you didn't twist on the cuts).

This has been the first report I have heard against the edge holding ability of 440V. What does surprise me and may be the problem is that you mention that it is easy to sharpen. Nemo / Fred and Steve Harvey have commented before that it is pretty much the opposite. I would expect this with the very high abrasion resistance 440V is supposed to have.

-Cliff
 
Cliff - As to the ease of sharpening, I use the Profile 700 of Spyderco (ceramic files) and was able to bring a sharp edge back with just 5 or 6 swipes on each side, using the fine stone. That means the edge on the Military wasn't deformed in any way. And since I don't know the bevel angle of the Military, I dare not use the Sharpmaker, coz it might give it a new angle, right?

As to sharpening the M2 AFCK, now that one took me some time to get it shaving sharp once again, using the same ceramic stones. I was expecting it to be the same as the 440V Military, but apparently not. The Military was a breeze to sharpen, I believe I didn't even hit 6 swipes per side, it might be even lower, before I got it shaving sharp again.

Maybe it's the RC?

Dan
 
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