Where does 440-C stand?

So the general consensus, witha few exceptions, is that it is a little tougher and more rust resistant than ATS-34 while holding an edge a little less but being easier to sharpen? Doesn't sound bad to me.

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Dennis Bible

....Almost here, The Leading Edge....
http://www.theleadingedgeonline.com
 
It is excellent knife steel when properly heat treated. I think my Puma White Hunter will last forever and its 440C.

It has all of the properties needed for a good knife blade and cutting tools but any steel that is not properly heat treaded is not worth its salt as a knife.

I think you will always see some of the better european knive companies using 440C
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Ron,
Bremerton, Washington
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For years all I used was 440-C,till 2 years ago when I went over to ATS-34.I agree that there is nothing wrong with it,but my selling went up with ATS,but I still use 440 when someone is worried about rust and doesn't want a black "T" coating.
Importance of the heat-treating can't be talked about enough.Not done right and you have a knife that won't hold an edge,or can't be sharpened.
As far as normal use 440-C is great and should be cheaper,it doesn't burn the maker's belts as fast,grinds faster easier to work.
ATS-34 takes chopping on rebar better,and pry-bar strengh is better,but most people don't use a knife like that anyway.
Dennis Phillips
 
My only experience with 440C is two customs I have , made locally by a guy that has been making knives for 35 years.

One is a fillet knife - heavy flex, easy to sharpen, quick to dull, don't remember the RC but it has to be pretty soft. The other is a nifty 'canoe' type slip-joint with one blade around RC59 and the other around RC61.

I can get all of the blades very sharp, the fillet knife is easy and a steel touches it up quickly. The RC59 takes a bit of work but gets and stays sharp, tough edge.

Putting the RC61 blade on a fine (600 grit or above)ceramic or Arkansas stone is daunting, it skids across like a butter knife on a piece of glass. But after a while, I get an edge that lasts a long, long time and is very, very sharp.

I've had both knives for over ten years and they both have developed a light 'haze', I think the former mirror finish could be restored very easily with a light buffing.

The maker switched to 440C early and has used it almost exclusively ever since because, as he says, "I can get it just right" I respect his knowledge and his skills and think that a 'well done' blade in 440C will out perform a 'poorly done' blade in ATS-34.

Steve-O

 
A German knife magazine (Messermagazin) tested 440C against ATS34 and CM154. They manufactured the same blade out of these materials. Edge retention in ATS 34 and CM154 was only slightly better than 440C. While 440C passed all corrosion test without any signs of damage the other steels suffered badly.
After reading that article (which seemed very objective to me) I'm going to take a closer look at 440C blades in the future. I had an eye on the BM 550 anyway.

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Seek simplicity, and distrust it.
Whitehead, Alfred North (1861 - 1947)
 
I really liked Rob Simonich's response. It is so true. Steel is a matter of fashion these days, not performance. 440C has been one of the best cutlery stainless steels for as long as I can remember and it's just as good today.

I prefer it to 154CM particularly if it's tempered a little softer. It is tougher and more corrosion resistant than 154CM at 60RC which, for me, is a little too hard and brittle for knife I actually use.

If they can get people to want 420 by calling it cryo-treated, I think it would be a major coup to reissue 440C with a sexy name. I vote for 4400 Enhanced.


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Fred
Knife Outlet
http://www.knifeoutlet.com
 
<font face="Verdana, Arial" size="2">Originally posted by Knife Outlet:
I really liked Rob Simonich's response. It is so true. Steel is a matter of fashion these days, not performance. </font>
Click to expand...

Ahh, the fashion parade. I have indeed found it amusing to follow the custom knife trends for the relatively short period of about 6 years now. "We don't want no stinking ATS-34 or micarta....too low tech!"

Please note that a number of custom makers have used Stellite for many years (Kit Carson, Herman Schneider, and George Young come to mind), well in excess of 10 years. In that light, Talonite can be said to be one of today's fashion kings.

Stellite, in various modern flavors, has been around as an alloy has been around for over two decades. Many say "Stellite ... yeah, that's the stuff that's similar to Talonite". They have the sequence backwards.

From a site on "Chronicle of Achievements of Elwood Haynes"

"Haynes Stellite alloys got their start as far back as 1899 when Elwood Haynes was searching for an alloy that would make a durable spark plug electrode." Haynes Alloy Digest, Sept 1953.

1907 December 17th. Received patent number 837,745 subject binary chromium and cobalt alloy. Patent number 873,746 subject binary chromium and nickel. Both patents cover a series of alloys.

1913 April 1st. Patent number 1,057,423 subject ternary chromium and cobalt with molybdenum.

1915 August 13th. Patent number 1,150,113 subject ternary chromium - cobalt - iron.


 
Food for thought, from a vendor, that may surprise you:

In Crucible's book "Tool Steel & Specialty Alloy Selector", they have some very general tables (designed for ease of comparison w/ bar graphs, and sans numerical data) that indicate the following:

154CM is maybe 20% more corrosion resistant than 440C
154CM has ~20% better wear resistance than 440C
154CM is ~25% tougher than 440C

They do not list the specific hardnesses at which they offer these comparisons, but do offer these "Typical Application Hardness Ranges"

154CM 58-62 Rc (Rc59 as air quenched, Rc61 oil, Rc63 oil+Ref.)
440C 54-58 Rc (Rc59 as air quenched)
420 49-53 Rc (only 0.36% carbon. That's why Buck uses a higher carbon version of 420).

I'm guessing "oil+Ref." means oil quench and cryo treatment.

By the way, Crucible's version of 420 is twice as tough as 154CM and has about 60% better corrosion resistance. Of course the tradeoff is about 60% less wear resistance, loosely translating into edge holding.

Conclusions from Crucible:
==========================
Corrosion resistance isn't all about pure chrome content. 420 above has 13.6% chrome, 154Cm has 14%, and 440C has 17.5%.

Similarly, Crucible indicates that CPM420V (14% Chrome) has about 40% better corrosion resistance than does 440V (17% chrome), which really surprised me also (420V is better in every way, edge retention, toughness at a given Rc, corrosion resistance. Prediction: It'll replace 440V in most places inside of a few years).

Corrosion resistance can vary depending on tempering temperature (per Crucible's book).

What the metallurgist at work tells me is that corrosion resistance of an alloy has everything to do with the corrosion resistance of the very thin oxide layer that develops on the surface of any alloy.

In the case of a carbon steel, that oxide is indeed ferric oxide or rust.

In the case of a simple chrome-moly steel, the predominantly protective oxide is chrome oxide from what he told me.

One could surmise that this would imply that it is the amount of chrome available to react with oxygen in the air (oxidize) on the surface of the metal (free chrome?) that governs this, but I am not so sure it's that simple. The idea is that free chrome is that chrome not already tied up with carbon in the form of chrome carbides. If free chrome were the driver, then 440C would probably beat 420 in corrosion resistance, which is not the case.

I have much yet to learn.
 
rdangerer: Interesting stats from Crucible! My gut reaction is: 154-CM more corrosion-resistant than 440C? Not in this universe! Same with toughness. The wear-resistance quote, I believe.

'course, now I'm thinking someone needs to do a definitive head-to-head.

 
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