What would you rather have AUS 8 or 440C?

[rifon2]

AUS-8A can be slightly harder and has a lower carbide volume so the edge can take and hold a high polish at a lower angle. 440C has a much higher carbide volume and a slightly lower hardness and thus requires a thicker edge and is best suited for coarse finishes.

-Cliff

In my experience, AUS-8A can take a remarkably sharp edge.
Some of my Moki knives, for example, made with this steel are among the sharpest knives I've ever had.

Recently bought a Benchmade (Snody)) Instigator, it is also phenomenally sharp, lthough its chisel grind makes direct comparison a bit tricky.

 

[gpdawg]

i have a linder stag skinning -5" blade and it says on the blade,"440 stainless and it has to be 440C as i finally had to use a wet wheel.doing it by hand i was spinning my wheels.

 

[Bob W]

My initial thought was to give a nod for the 440C. My EDC is AUS-8. Gets shaving sharp, but doesn't stay that way for long.

After reading the others' posts I'm not convinced one way or the other.

-Bob

 

[Michael Lovett]

Thanks Cliff! But you can be confusing. You said that you weren't thinking about AUS-8. Hee! Hee! Just picking on you. Edge on, why are you being rude? It isn't required to post here. 440-C is not a generic term. 440 stainless is on the other very generic. 440-C is a Cutlery grade stainless designed by Carpenter Steels. It is a very high quality steel. In fact the famed 154-CM is listed by its maker, Crucible Metals, as Modified 440-C. 440 Stainless can can be just about anything. Especially from china. They do not go by AISI Specs. Even worse is blades marked 400 Series stainless. Can we say Kitchen counter tops? I use 416 in the shop for all my guards. It goes into service at 37-41 Rc. Depending on how I heat treat it. Would you want this For a blade? I don't thinks so! I still know of no Chinese knives being made of true 440-c. If they are, it is a recent thing. Taiwan is another thing. Generally higher quality. However, the Chinese are putting out vastly better quality knives than just 3 or 5 years ago. So may-be. I do know that ATS-34 got really scarce a couple of years ago. So much in fact, that Loveless and I split the last stockpile in the US that we could find. Guess where it was all disappearing to? CHINA!!! They weren't using it for knives though. Can we say High performance Jet turbine steel? I smell trouble!!!

 

[Jeff Clark]

I have rarely found any 440 series blades that would take a thin edge as well as any member of the AUS series. Since I really like thin edges I prefer AUS-8 to almost any 440. I wonder if cryo treatment would help 440C.

 

[Michael Lovett]

I have rarely found any 440 series blades that would take a thin edge as well as any member of the AUS series. Since I really like thin edges I prefer AUS-8 to almost any 440. I wonder if cryo treatment would help 440C.

Yes it does! As I said, 154-cm, and Ats-34 are modified 440-c. 154-cm was the first cutlery stainless to be cryo'd to any extent. By Bob Loveless who pioneered the technique in Knives.
I have ground many a hunter at .007 at the edge. Some even thinner. I like .015-.020 the best. at 60-61, properly heat treaty 440-c, 154-cm, and ATS-34 will flex at the edge without cracking, Chipping isn't an issue. AUS-6 and * tend to roll the edge at these thicknesses. I don't know many custom makers that will use it. Right now, I can't think of a one. It is cheaper, and easier to grind, and much easier on tooling. If it was all that good, we would be using it. We want to make good quality knives, but we also like to make a living. this should just about say it all. AUS-10 is of higher quality, but still I don't know of a maker (Custom) using it. Let me know if you do. A good friend of mine, Kit Carson, has had a lot of his design knives using aus-8 make by Columbia River. But you won't find one made by kit in this steel. Kit, like myself can use anything we want. There are reasons for ever thing. Aus first appeared in Taiwanese knives. Not Japanese. I know of no Japanese knife company using it either. I have seen knives out of Europe in AUS steels. Is it really Japanese steel. I was under the impression that it was developed in Germany. But I can very well be wrong. Mike

 

[Michael Lovett]

OOp's! I must apologize. I just noticed that this thread is in the Blade discussion Forum. For some reason, I thought I was in the Custom forum. Totally different worlds. The Bar is set at way different levels. My Bad. Mike Lovett Maker, celebrating 33 years in the knife making buisness.

 

[Frank Hillary]

Hi Cliff,

You sand others eem to be saying that the carbides in 440C get in the way of a thin edge. What is theuir diameter?

Best Reagards
Frank

 

[thombrogan]

AUS-6 and * tend to roll the edge at these thicknesses.

At which hardnesses, though? AUS-8 at RC58-59 is a different beast than AUS-8 at RC55.

I don't know many custom makers that will use it. Right now, I can't think of a one. It is cheaper, and easier to grind, and much easier on tooling. If it was all that good, we would be using it.

It is a very good steel, but so many people are used to seeing it in knives costing between $19.95 and $100 that even higher-priced factory blades with AUS-8 are a turn-off. Blame Fred Carter, Bob Dozier, Ernest Emerson, Sal Glesser, Ken Onion, Lynn Thompson, and Ken Warner for no one wanting to pay big bucks for a Lovett AUS-8, but don't blame the steel.

Actually, since 1095 can be found in both $10 Old Hickory kitchen knives and super expensive custom knives, maybe you can bring in the big bucks with AUS-8. If AUS-8 chute knives were being hand ground and heat-treated by Mr. Michael Lovett himself (with certificate of authenticity), maybe it help folks know the steel is the real deal.

I know of no Japanese knife company using it either.

G. Sakai Company has used it for Cold Steel, Emerson Knives, and Spyderco. Now you know.

 

[Cliff Stamp]

What is theuir diameter?

Above 25 microns.

AUS-10 is of higher quality...

AUS-10 s not of higher quality than AUS-8, it simply has more carbides. I would be curious to know what you think of AEB-L as that has almost NO carbides at all. The Sandvik series steels are used by many high end knifemakers.

I wonder if cryo treatment would help 440C.

No, because it is simply a matter of carbide volume/size. If you wanted to address this issue you would soak at a really high temperatures to dissove the carbides and then quench really fast + cryo to prevent precipitation and reduce retained austenite. But this is kind of absurd because the reason for the high chromium in 440C is to in fact produce all those carbides for wear resistance.

-Cliff

 

[Michael Lovett]

Cliff, sub zero will indeed improve 440-c's edge holding. I haven't used any higher Rc. Aus blades. All I have owned easily rolled the edges. cold Steel? enough said. Spider co, Lower line, check it out. Emerson? I was wondering why the controversy recently about cost vs, quality. Personally I have no Idea about them. But do a search here. It is all here. Including a lot of usaer in-put on the aus steels. This in not a new topic. cliff. I didn't say anything about carbides. I have nothing against carbides in this instance. As I have said before, I finish out my knives very thin. I have used 440-c for decades. (no longer as all Loveless connection Knives are 154, or Ats.as per bob Loveless). I can take my Carson Colombia river m-16 and cut curls off of a pine 2x2 here at the shop, and it will loose it's guilt edge in 4 or 5 passes, Still cutting, but not hair popping sharp. The M16-T in Aus-8 will do a couple of dozen. My 440-c hunter will at least 150. 154-cpm, add another 75-100. Every aus steel knife I have ever tested was good to poor at edge retention. None were very good. Not even excellent. Much less superior to much of anything but 40 s/s, or 420. You must be getting some excellently heat treated, and ground blades from these low cost knives. What make are they. I would love to be able to ell my customers there are low cost, super knives out there. But you said your self that they are low cost knives giving the steel a bad name. How does it give the steel a bad name if it performs. very contradictory. either they are good, or not. Either they preform or not. Which is it? I have a Kershaw Leek here that is about dead between Aus-4 and Aus-8. It will barely hold an edge long enouth to get into the pocket. But it does out class the Aus-4. Both are terrible. I would like to test Aus-10, but i'm not finding any. You are probably correct. Aus-10 probably isn't superior. No more Than a fine watch is superior to a cheap watch. Come on Cliff now your trying to argue just for the sake of arguing. You know full well that that last statement is full of it's self. Get real!

 

[rhino]

One was 440C and the other was AUS 8. Now, I know there are alot of other factors that are involved in choosing a knife but let's say, all things being equal which steel would you choose?

AUS8A without hesitation. I can get a much sharper edge, regardless of how long I have to work on it. I've had several knives made from 440C and none produced satisfactory results after I reprofiled the edges (I like them as thin as I can get them), and thanks to Cliff Stamp, I have a little understanding as to why that may be true. I've only had one knife (of many) made from AUS8A that did not produce excellent results, and I choose to attribute that to a poor heat treatment.

 

[Cliff Stamp]

Cliff, sub zero will indeed improve 440-c's edge holding

In general you would expect this of cold treatments because of the changes to retained austenite. Clark however was speaking of edge stability which is different. It will also help there as well, but the large segregated carbides will be the main problem and cryo does nothing to them unless you do what I noted which as I said makes no sense anyway because you are basically trying to turn 440C into 440A.

All I have owned easily rolled the edges. cold Steel?

No, heat treatment. As I said, look at the references. AUS-8A has a slightly higher max hardness than 440C, not lower.

Either they preform or not.

Many companies are using the AUS series in their lowest end knives and thus the heat treatment suffers corrospondingly. This however is no more the fault of the steel than it is the fault of 1095 that TOP's knives don't cut well.

In terms of quality, you seem to be equating quality to carbide, not directly but this is exactly the difference in the steels you are listing. They are higher in wear resistance due to the carbide type/volume. This is why I asked for your opinion on the Sandvik steels.

Those steels are well respected but they have almost no carbide volume.

-Cliff

 

[psy-ops]

The BYrd series is advertised as 440c.
Boker-Nealy, specialist and the paracord version are touted as 440c.
Mission's MPU ss is advertised as 440c.

I think all are made in China.

 

[Frank Hillary]

Hi Cliff,

Thanks for that bit of info. I take it that you mean metric microns, not inches.

Best Regards
Frank

 

[Danno4017]

I have several knives in AUS8 and find them satisfactory.
They readily sharpen and hold a reasonable edge.
Having to give the edge a touch up now and again is no hassle I like sharpening things.

 

[Cliff Stamp]

Yes, D2 is larger still at about 50 max. Landes really focused on carbide volume/size in his work on steels. He talked about the NEGATIVE aspect. This is why he prefers 440A/420HC over 440C for a knife steel. Yes he is a custom knifemakers and yes a lot of european knifemakers feel similar and use low carbide steels for knives.

-Cliff

 

[Sal Glesser]

Hi Michael,

The AUS series of steel is produced by Aichi in Japan. Liked 440, the steel composition of each (4,6,8 & 10) is the same, but the carbon amounts vary.

AUS-8 is a very homogenous steel in terms of grain size, which is why it will get so sharp. It looks similar to powdered metals under an electron microscope.

ATS-34/154Cm doesn't have near the chrome content of 440 series. Hard to compare them as steels. I would have a hard time imagining Crucible saying they were the same?

You need to check out some of Spyderco's "lower line" ZDP-189 or CPM steels. Might surpise you in the performance? Certainly above ATS.

Hi Chrisaloia,

byrds are made from 8Cr13MoV at this time. The first run was marked as being 440C, but they never were made from 440C, those were mismarked. It was corrected after analysis.

sal

 

[psy-ops]

Thanks Sal,

Does 8Cr13MoV, have any similarity with other factory steels?

I know this is how these very informative debates start but for us layman it generates some from of reference.

 

[Sal Glesser]

8Cr13MoV would be comparible with AUS-8 in chemistry. They are also comparible in performance. We run the 8Cr13 a little harder. AUS-8 seems to perform better in corrosion resistance (not sure why, maybe the tad extra in carbon eats up more chrome?).

It was the best performing steel we could find in China at the time. We're playing around with a higher carbon, higher chrome steel now.

Foundries worldwide seem to be competing more lately for better performing steels. Good for us knife junky's :thumbup:

440C is an excellent steel. Especially in corrosion resistance, and it still gets hard. We used 440C to make the "whale rescue blades".

AUS-8 is an excellent steel, especially in taking a very fine edge.

All good, just different.

sal