440 Hc

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sevenedges

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I 've looked around a bit , did a search and didn't find out too much info on 440 HC. I'm sure it's been covered a bit, but my question is how does this differ from say 440 A? I noticed the LUDT from Microtech is now made from this and am looking at buying one. The type of steel doesn't matter to me nearly as much as it once did, due to the fact that I can make anything incredibly sharp in a few minutes. My main concern anymore is durability and most importantly rust resistance. Cliff, I looked at your homepage and didn't see anything on it about 440 HC. Your opinion would be appreciated, as well as anyone else who has used the steel for a while. Thanks,
Jeff
 
There is 440 A, B and C. They differ in carbon content.440A is found in cheap knives and doesn't make very good blades. 440B makes a reasonably good blade [good for chopper]. 440C makes an excellent blade with good edge retention. The term 440HC doesn't mean much , are you confusing it with 420 HC ? Look for Joe Talmadge's steel guide in this forum. Also see the steel guide for chemistry on www.agrussell.com
 
orthogonal1 said:
I was under the impression that 440HC was like 440C, but with a bit more carbon.
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I don't think so. You could easily refer to 440A as 440HC. I've never heard of a steel that is 440C with higher carbon; I'm sure a similar steel has existed at some point or other, but it was never called 440HC.
 
I am familiar with the other three grades of 440. I really don't even like 440C, although I like the rust resistance. Seemed a little too malleable to me the last time I used it. (Cheap Boker neck knife) Could have been the heat treat. Some people love it. Preference I guess. More carbon would make it better, in trade for a little rust resistance. I could give it a try. Just don't know why Microtech would drop to a lower grade of steel (IMO) when 154 CM would suit many people fine.
 
On the Microtech website, they list the steel for the LUDT as "BLADE: 440 HC, RC 56". I couldn't find any further information on what's in it.
 
Larrin said:
I've never heard of a steel that is 440C with higher carbon;
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Carpenter makes 440-XH and they describe it as basically a harder version of 440C, it can reach 60 HRC with just air cooling, or a more corrosion resistant version of D2. It would indeed be well described as a P/M 440C-HC.

mete said:
There is 440 A, B and C. They differ in carbon content.440A is found in cheap knives and doesn't make very good blades. 440B makes a reasonably good blade [good for chopper]. 440C makes an excellent blade with good edge retention.
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440A is not simply a cheap knife steel any more than AEB-L is for cheap knives and ATS-34 for excellent ones. 440C has a huge carbide structure and thus has much lower edge stability than 440A this lowers its ability to hold fine edge to a high sharpness or even obtain them, which is why makers such as Landes prefer 440A class steels over 440C for their knives. 440A is also much more corrosion resistant and tougher.

sevenedges said:
I looked at your homepage and didn't see anything on it about 440 HC.
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The HC label is not overly distinct, you generally want a specific designation, a reference to a particular steel type, rather than basically a note of a modification as this can be very open ended.

-Cliff
 
Wouldn't 56 be awfully soft for that steel- if we're assuming it's based on 440C?
 
Cliff Stamp said:
Carpenter makes 440-XH and they describe it as basically a harder version of 440C, it can reach 60 HRC with just air cooling, or a more corrosion resistant version of D2. It would indeed be well described as a P/M 440C-HC.
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But it is not 440C with higher carbon, there is no designation for such a steel. There is no 440HC or 440D. I am sure that such a steel has existed at one point or another, but not in widespread use.
 
Cliff Stamp said:
440A is not simply a cheap knife steel any more than AEB-L is for cheap knives and ATS-34 for excellent ones. 440C has a huge carbide structure and thus has much lower edge stability than 440A this lowers its ability to hold fine edge to a high sharpness or even obtain them, which is why makers such as Landes prefer 440A class steels over 440C for their knives. 440A is also much more corrosion resistant and tougher.
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And like I've told you before, Landes is not referring to 440A, he's referring to a high carbon 420. Many steels are referenced as a 440A similar steel. 440A is not a good blade steel. It doesn't get very hard.
 
hardheart said:
how hard does 440A get, I've seen a couple references to 57-60, with 440C at 58-61
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There is a possibility you could achieve 60 Rc with a relatively high austenitizing temperature, cryogenic, and a 212F temper, but since 440C is brittle at 60 Rc I don't see the point of taking 440A that high. And contrary to what Cliff has said, 440A doesn't have small carbides, it doesn't have a lot of carbide, but they are all larger primary carbides.
 
Larrin said:
And like I've told you before, Landes is not referring to 440A, he's referring to a high carbon 420. Many steels are referenced as a 440A similar steel. 440A is not a good blade steel. It doesn't get very hard.
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As I told you when you last brough that up, he is speaking of a general way to think of steels (edge stability) and doesn't restrict that viewpoint to one steel in particular. 440C has a huge carbide structure (50 microns) and is even far worse than the steels like ATS-34 which have a very low edge stability because 440C retains as cast carbides. Simply having a high wear resistance doesn't mean a steel is superior for knives.

440A has a higher max hardness than 420HC which Buck hardens to 58 HRC. The difference in the 440 series is actually small enough so they overlap in the elemental tolerances. 440A at the upper and high carbon/low chromium composition actually is on the same tie line as 440C with the low carbon/high chromium composition. Thus while the average performance would be different you would expect considerable overlap in the batches of knives you made from those steels.

Larrin said:
But it is not 440C with higher carbon, there is no designation for such a steel.
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HC isn't an official designation in that sense, it simply refers to a steel with a higher carbon content, just like ATS-34 is refered to as 440C-mod by some manufacturers. 440-XH is described as a high hardness version of 440C so it would be natural to refer to it as 440C-HC because that is the essential difference.

-Cliff
 
Cliff Stamp said:
As I told you when you last brough that up, he is speaking of a general way to think of steels (edge stability) and doesn't restrict that viewpoint to one steel in particular. 440C has a huge carbide structure (50 microns) and is even far worse than the steels like ATS-34 which have a very low edge stability because 440C retains as cast carbides. Simply having a high wear resistance doesn't mean a steel is superior for knives.
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But 440A also has large carbides, just a smaller volume of them.
 
Cliff Stamp said:
440-XH is described as a high hardness version of 440C so it would be natural to refer to it as 440C-HC because that is the essential difference.

-Cliff
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Interesting. Described where? Are you sure it is 440C they are talking about?
 
What 440HC means is that they won't tell you what the real steel is. Same as saying surgical stainlerss. It's a lack of description as opposed to being specific.

Gene
 
440HC [chin in hand]. That gives me an idea though. I have some 440 knives but the steel is so soft it doesn't get very sharp and wont hold an edge. I think I'll get some carbon and make the edge red hot and try to put carbon in the steel and quench it. If it is better ok if it is worse it didn't have much use anyway.

420 might be too hard to put carbon in even for the experts. Case might be the only ones that know how.
 
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