Question on steel

dialex · #1

Actually it's not steel but titanium alloy (I guess steel involves carbon and iron).

So there are those guys at "Mission Knives" claiming they make the toughest knives on the planet (like many others <img src="wink.gif" width=15 height=15 align=middle border=0> )They use a precipitation hardened titanium alloy, that holds a shaving edge, better than stainless steel (according to their statement). Now I wonder about the hardness of this alloy as I've learned that titanium is not suitable for blades because it's soft (about 40°Rc).

Thank you very much in advance.

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Sword and Shield · #2

From what I've heard, titanium will hit, at best, an HRC of around 50. That is soft enough to sharpen really easily, but it won't hold an edge worth a darn in any impact testing. Ever wonder why all Mission knives have serrations? Now you know. <img src="smile.gif" width=15 height=15 align=middle border=0>

By the time you read this, you'll have already read it.

ronin203 · #3

I also have a question. I have been collecting knives for years but don't know a lot about steels. What' the difference between cpm440c and cpms30c?

Sword and Shield · #4

OK, lots of generalizations follow, so be ready.

440V (90V)- very nearly a high-carbon steel. It has huge amounts of carbon in it (>1%), and thus is very agressive as a cutter. Due to the high carbon content, it is also a chore to sharpen, but will hold an edge nearly forever.

30V- 30V seems a little odd. Based on the things I've read, this is either the new wondersteel, or a pile of slag not worth mentioning. Supposedly, it solves the corrosion problems 440V has, with only a slight loss in edgeholding. It is also supposedly easier to sharpen.

Hope this helps. <img src="smile.gif" width=15 height=15 align=middle border=0>

By the time you read this, you'll have already read it.

dialex · #5

The S30V has nitrogen, just like the Busse Infi steel! It acts like carbon without "stealing" the chromium.

Edited by - dialex on 5/13/2003 12:12:40 AM

ronin203 · #6

Thanks for your help guys.

Ed Schempp · #7

Crucible Steel has a great website with all the specs on thier steels. From memory I believe S30V has about 3% Vanadium, 1.45% Carbon, 14% Chrome. S60V formerly 440V Has about 5.5% Vanadium, 2.5% Carbon and 17%Chrome, S90V formerly 420V has About 9% Vanadium, 2.5% Carbon and 14% Chrome. CPM technology allows for the production of high Vanadium Steel hence the number relates to the precentage of Vanadium content. Vanadium carbides are the hardest of all carbides and have a very strong affinitey for Carbon and will take priority over iron so you have to have enough carbon to make the Vanadium carbides and still have enough to make martinsitic steel.

Dave I · #8

to:sword & shield, Correct me if I'm wrong but 440v's new # is S60V not S90V. I've been using a Random Task for over two years now CPM440V and have never had any corosion problems. I even lost it this past winter but found it frozen in the snow & ice where it had been for a while. Brought it in thawed it out, dried it out and put a couple drops of oil on it and it's like new again.AS far as keeping it razor sharp when it gets a little dull I take it to the canvas side of my barber shop type strop and after about 10 swipes it will shave hair again. I only had to take it to the stone once after it cut through the hard rubber exhaust pipe hanger so fast I hit the bolt quite hard & put a tiny nick on the edge. That nick came out quite easy on the stone.
I think this blade will out live me. I just picked up a NATIVE S30V and it's great. A friend of mine has a NATIVE S30V and told me it's just as good as my 440V Random Task. That's why I got the NATIVE in S30V.
Dave.

icebj¿rn · #9

Hi all,
Just wanted to post something about the titanium alloy.
One factory in Solingen also produces titanium blades and
they told me something about this.

Basiclyhis alloy is a particle titanium added with carbids and silver.
It is pressed, sintered and the cold forged.

It holds edge quite as long as ceramic blades do, but is more flexible.
I have seen knives being smashed onto the ground without breaking them.

Adding carbids and other elements increases the the hardness of an alloy.
It is very difficult to add elements to the hexagonal structure of Titan,
but when this is done it gets hard enough.

Edited by - icebjørn on 6/30/2003 5:53:30 AM

dialex · #10

What does it mean "hard enough"? AFAIK, they never made titanium over 50 Rc.

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