Titanium (mission knives)

C

Cliff Stamp

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How well does the Titanium in the Mission MPK hold an edge. Would it be on par with 440A or even lower say 425, or still less than that?

How durable is the edge? Will it chip out if used to chop through harder materials or will it just impact, and if so how badly does it get indented?

What kind of edge will it take? Can it take a very high polish finish? How about a very coarse aggressive one?

Does Titanium offer any advantage over the steel versions besides being non-magnetic and corrosion proof?

I am looking to get one of the MPK and want to get a feel for the performance I can expect. I pretty much can guess how the A2 would behave but have never used one of the Ti blades.

-Cliff
 
Cliff, I have one but have not really used it hard. It is definitelly tough as I did do some prying with it. As far as chopping goes, it is really light which does not help in chopping.

As far as edge holding, it appears to be like a 440A blade or so. I have not chopped with it so i'm not sure if it can hold up to chopping but it should not chip since TI is very ductile. I cannot put a great edge on it as I can with regular steel. It's either because I'm not good at it or the Ti is softer making harder to edge it, or a little of both.
 
And of course I forgot to mention one of the more important aspects - does the false edge weaken the tip significantly. Can you for example dig in wood with it?

Cobalt where is the balance point located?

-Cliff

 
Cliff:
There was an article that came out 12 to 18 months ago in Blade Magazine on a Ti knife (6AL4v) I think. Looked for the mag but couldn't find it so this is from memory. The Rc was around 45 and wouldn't take a very keen edge but was able to keep the edge it had very well. They cut various materials, hacked, chopped and dug and I think did some prying without dulling the edge.
What little I have used it, on the Uluchet proto handles, it is verrrry abrasion resistant. If I come across that article I'll post the correct information.

------------------
P.J.
YES,it is sharp, just keep your fingers out of the way!
www.silverstar.com/turnermfg


 
I have the MPK and I have used it for some time now.

Chopping is not good due to the light blade but with enough energy it lets the chips fly. I have never chipped the blade so it seems to be OK and not prone to chipping.

The edge ..... actually the Rc reading is mid 40's. Edge does not feel very sharp and I have never managed to get mine shaving sharp. It does take an edge that is sharp and it keeps if very well but the edge is more agressive than polished.

Prying with the blade .... I have managed to get some alarming flex in the blade but it returned to true every time ...the flex was about 40 deg. The sharpened false edge doesn't seem to weaken the point as mine has stood up to digging holes in wood with no damage.

Overall, unless you require the corrosion resistance of titanium or the magnetically inert properties, I would opt for the A2 ....I have ordered one already.

My 2 cents

Aubrey
 
Personally, as Aubrey mentioned, unless you require the special properties Ti has, most people who actually use the knife would be better off with the A-2 version. If you want something cool to admire under a banker's light that requires zero maintanence, its the blade for you :-)

The one caveat that I will mention that people may be over looking is its weight. As mentioned, this is not an asset when chopping but, in a neck knife, I think an asset. When you add the corrosion resistance, that hot Texas sun and lighter weight for a large neck knife seem like a good combination for me.

While I lack personal experience with flexing and other brute strength issues, I have spoken with Mission about this and doubt I would personally ever chip or break the blade, false edge or not, with anything I would do with it with my bare hands. I am not the most strenous user out there so, take it for what its worth. A phone call to Mission would be your best bet for a detailed explaination of what to expect with your intended use.

As far as Ti flexing and returning to true, I can speak from experience with my eyeglasses. The frames are Ti and have a memory that is incredible. Through various unexpected tests, I have had them mash'ed flat when open and spring back to true. With heavy glass lenses if they didn't spring back exactly, I would have a sore spot from the weight on my nose or ears and, if bad enough would notice the misfit on my face from unequal tension. I know there is a difference in eyeglasses and knives but, at this time I have much more real experience with Ti eyeglasses.

Sid

p.s. The 10" A-2 MPK's should be here mid-week if all goes as expected.



------------------
Sid Post
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I am a dealer for and stock:
Mission Knives & Tools, Inc.,
Tactical OPS USA from Idaho Falls, ID,
Chris Reeve Knives,
the Krill Lamp from Kriana Corp.,
Underwater Kinetics flashlights and,
Streamlight Flashlights,
with other fine products being added as they are found and time allows
 
For reference I discussed (email) this issue with Mission awhile ago. In particular I was interested in the toughness of the blade in Ti and A2. Mission's opinion was that the Ti blade should be much tougher than the A2 version.

Sid what does 10" MPK mean, that's not blade length is it?

-Cliff
 
Greetings to all.
Wouldn't you know it, the weekend I decide to take off inspires a discussion on our products :-)

Anyway, here is a summary...
1) Edge holding - all things being equal, our Ti blades will hold an edge equivalent to a 440A knife. But, the more extreme the environment, the titanium will not be affected, but the steel will deteriorate more quickly. An example, a few years ago, while I was visiting a customer (Coronado Seal Team 1), they laid an O1 tool steel knife (I'm sure you know which one I am talking about) out on an outside workbench. It had a razor sharp edge. At the end of the day, we went back to take a look at it. The edge was starting to turn orange. This knife had not been used and could barely cut a piece of nylon line.
2) Durability - In all of our customers continued feedback, the Navy has only broken one knife - and that required a 250 ton ram press. I have not heard of any blades even chipping, and that includes chopping through the metal banding on C4 cans, ripping through the metal banding on ammo crates, and chopping through (using the tip) solid oak planks. The blade will flex considerably more than steel, but I have always seem the Ti return to true.
3) Sharpness - Ti is a bear to sharpen. The reason is that the burr just flops back and forth, back and forth. On a steel knife, the burr can easily be removed with a felt or rubber type wheel. On titanium, the burr is very difficult to remove. I have seen only a few people master titanium sharpening. One of the best is Kim Breed. We recommend using diamond. On extremely difficult burrs, I sometimes use my fingernails to peel the burr off! Also, the edge geometry on the MPK lends itself to more of a utilitarian tool - all around use such as chopping, prying, the things you shouldn't do with a knife, etc. The folder has a much better edge geometry for slicing.
4) Aubrey - has been a very good customer and provided great input to help us build better knives and tools. Actually, let me say that Mission has a GREAT bunch of customers. Anytime we need input, all I need to do is place a question on the forum or via email and we get nearly 100% response. I feel fortunate to be involved with a great bunch of people. We try and treat our customers as "part of the team" and it really shows!
5) Sid - is one of the Authorized Mission Dealers and has also provided invaluable help and support.
6) Steel knives - we are augmenting our authentic and proven designs now into steel -primarily A2. These knives will be considerably less expensive than the titanium knives, and provide a great deal of quality and value. We will be placing some disclaimers on the steel knives though. We do not recommend the steel knives for demining, scuba diving, prying, chopping, etc. Hardened steel is much less ductile and durable than hardened titanium meaning hardened steel is much more likely to break, chip, or snap when used in an extereme application. To help circumvent this, we will be lowering the hardness a little. Based on the testing and analysis we have completed, A2 performs best as a knife blade at RC56-57. That is where we are targeting our hardness. The 10" MPK-A2 Sid is talking about is the new 10-3/8" overall length MPK. Should be a knife in great demand.

Sincerely,
Rick

 
Rick, I understand about the corrosion aspect of the MPK's etc. But, concerning your comment about the O-1 steel knife loosing it's edge just sitting around all day does not make any sense. Think about it, it did not go into the water, nor did it get used and it lost it's edge. I'm not calling you or anyone else a liar, but I cannot believe that one. I know just a teeny little bit about corrosion rates and I don't think that you could loose an edge that fast, even with bare O-1, much less with hard chromed O-1. As has already been discussed, Hard Chrome provides slightly more corrosion resistance over tool steel. In fact some of the rates I have seen published are that a hard chromed steel will last about 20 times longer in the same circumstances than a regular non hard chromed steel(different steels will vary of course). It takes at least 2 hours for a regular steel to start showing spotting in a salt test. It would take all day to get to the point you describe in a "salt spray test". And on top of that with the hard chrome it would take a whole lot longer. And what you witnessed was not even as bad as a salt test.

Rick, not to call you or anyone else a liar, but I'll believe that when I see it, because I can't believe it.
 
I can run my car without oil and seize the engine, but I wouldn't consider this a fault of the car. I use steel knives all the time in all kinds of environments and have found that with even very minimal care, they remain free of corrosion. As basic as a rinse of fresh waster and a blast of WD40 keeps 'em free of gunk and rust.

I've heard great things about the Mission knives as far as being great dive knifes, but I would find it hard to fault a neglected tool with corrosion any more than you can blame a dirty firearm for improper function.


--Doug
 
Cobalt it depends on the humidity. I have seen knives rust enough to discolor left just in the outside air. I do however live right next to the sea. I can test this out quite easily with reference to the knife in question. I do agree with Doug however this is rather meaningless as I never leave my knives lying around all day long. If I did it obviously means I didn't need to take it with me.


-Cliff
 
Cliff, since we were talking about an unused knife that just sat on the table, do this; Wipe off the blade to make it look as new as possible and do not coat it. However, coat the broken portion with marine tuff cloth so that the salt water spray in the air has togo through the hard chrome first. I'm betting that you will not see any change in the blade's edge in a day or even two days. My guess only though.
 
I have personally had ATS-34 rust on me in under a 12 hour period of neglect in my pocket. Granted, it was only light surface rust, but rust none the less. If I had a tool steel knife in my pocket, I would have had a big rust stain to take out of my pants.

The environment you are talking about makes a lot of difference. Also, even in "coated" knives, the cutting edge is exposed base metal - whether it is rust prone carbon steel or San Mai stainless.

Sid
 
All this talk and speculation has me getting steamed. Theres only one way to settle this, lets do it up right.

Somebody get a hard chromed ATAK or other Mad Dog Critter and put it in Seawater for testin. Lets all see what happens then, hey?

If the hardchrome is good, nothin will happen. If not, we'll truth will be told.

Whos gonna volunteer their knife?

Chawdawg

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Chaw tham up, spit tham out.
 
Cobalt, the edge that Rick is talking about was probably uncoated. Even if you do coat right along the edge with Marine Tuff Cloth it will get rubbed off as soon as you do any cutting. One of the reasons I am beginning to like leather sheaths more is that they automatically relubricate the knife when you resheath it (because of the oils they absorb).

If you back at some of the old posts in rec.knives you will see this argument come up again and again. In corosive enviroments with a stainless steel like 440C hold and edge better than a good tool steel like O1? The only actual published test I have seen was in JJ (The Razor's Edge Guide to Sharpening). He stated that he had two knives made of the same geometry by the same maker. One was a high carbon steel and the other a stainless one. The stainless steel far outlasted the high carbon one in terms of edge holding. It was on meat cutting I think.

If I am not mistaken then MPS has made a number of similar comments about him prefering softer stainless steels over much harder high carbon steels in corrosive enviroments because the stainless ones hold an edge better. This is in regards to kitchen knives and filleting knives.

However I have also seen the exact opposite claimed. More than one person has done corrosion tests on MD and other knives and the MD's edge remained functional while the others (some stainless) has rusted away. This boggles me somewhat and all I can figure is that while the corrosion was greater on the MD it for some reason effected the edge less. This might be do to the finer grain structure on the O1 staying more stable even after suffering more corrosion.

In any case I have a piece of the knife in question and I will repeat Mission's test and see how long the uncoated edge has to be left out in order to lose its edge. I can then send it to Cobalt and he can duplicate it. If his results differ then we can meet in an empty alley with drawn khukuris and settle the argument the civilized way
smile.gif


-Cliff
 
Cliff, sounds good to me, and I agree that 440C or any of the 440's for that matter are excellent around salt water. But I just find it hard to believe that in basically 12 hours a hard chromed O-1 knife lost it's edge. I guess we will see.

Oh, and 20 inch Sirupati's at 2 paces.
 
Sid do you carry the Ti folder from Mission? I was checking out the specs on:

http://www.missionknives.com/products/mpf.html

And it looks like what I have been interested in getting for awhile now. I usually have one folder on me that cuts really well as its nice and thin and hard, and another that is more durable but not as good a slicer. The first one gets most of the cutting jobs, the second gets any prying/chopping and also a lot of the messier jobs that tend to leave gunk on the blade as well as any cutting done on harder materials. Its usually a cheap, thick, soft stainless blade.

The MPF looks ideal as a replacement as the Ti blade should resist getting damaged by corrosive elements obviously, and looking at some of the comments above it should be easy to maintain when used to cut tough materials. My only concern is will prying damage the lock mechanism. Namviet has commented in the past that he has pried with his MPF and I was wondering what is Missions policy in regards to this?

By the way is the only version available still the 4" partially serrated one? What's the price?

Cobalt, forget Sirupatis, I am bringing a 38" Janawar.

janawar.jpg


-Cliff

[This message has been edited by Cliff Stamp (edited 30 March 1999).]
 
Cliff, that's not fair!!

If your bringing that behemoth, then I'm going to bring, heck, I'm not going to show up. That's the one that they use to sever the head of a cow or bull, right?
 
Good morning...

Cliff-I have a video of a prototype MPS hardened to RC47 that was placed in a vice. We used an 18" pipe wrench to bend it and see where the breaking point was. At over 45 degrees, the vice broke and came crashing to the floor! The knife was undamaged and unbent! I will eventually be putting this on the website.

Cobalt-Have you been to Coronado? The SEALs are on the ocean side of 75. Their compounds are about 100 feet from the ocean. Believe me, there is plenty of salt spray and salt mist mixed within the fog. This knife was outside on one of the benches and was probably exposed to an equivalent of your salt test just sitting there. Hard chrome- you are making an assumption that there was hard chrome on the blades. First off, after sharpening, there is no longer any hard chrome on the cutting edge of the knife. This was one of the problems. When the knives would get wet, the sea water via capillary action would work its way up between the coating and the steel blade and would cause the hard chrome to flake off! Also, the action of rubbing the knife against the kydex sheath would tend to wear off any remaining hard chrome. Since we are on the hard chrome subject, did you know there is no hard chrome on the tang of the knife? If there would be, then the epoxy would not be able to glue the handle to the tang. I saw one such knife that the handle had fallen off. The tang is not completely sealed thereby allowing sea water to infiltrate the tang area. Rusting ensued, thereby causing the epoxy to fail. The handle fell off. I know what I saw, along with the two other (I cannot mention names here) SEALs that were present.

Doug-Thanks for the input. Remember, that particular O1 knife was advertised as a dive knife for the SEALs. Not one steel mill recommends using O1 for salt water applications. Also, SEALs often do not have the luxury of having a lot of spare time. Items get rinsed off and hung out on the chain link fences to dry. These items then get placed in the "cargo/shipping containers" at the rear of the compond. The inside of these containers are hot and humid and smell of mildew and mold. Hell, the SOG SEAL 2000 nylon sheaths rotted completely away just sitting in one of these ST5 containers. As for the SEALs, I have been told that any spare time left for maintenance will be used to keep the firearms in working order. Rubbing tuff cloth or oil on a knife will never be done.

Chawdawg-The Navy already performed this test. That is why the second time around they requested stainless steel and titanium knives.

Cliff-Please see our corrosion test http://www.missionknives.com/articles/CorrTest/index.html

Hope this explains it a little more.
Rick
 
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