400SS or Aus8?

[zakjak221]

Is there a way to tell the difference between these two?

 

[jlauffer]

Is there a way to tell the difference between these two?

Not that I know of, but I wouldn't be surprised if they were actually the same. And if they are different, the difference is probably so small you wouldn't notice it with normal use.

 

[TheFlash]

AUS-8 typically has more other components (e.g. vanadium, manganese, molybdenum, nickel, etc.) and enough chromium to make 'stainless'.
I think the 400SS is a 'simpler' steel with fewer additions that add strength and wear resistance.

Hope that helps...

 

[jlauffer]

The 93-94 catalog has 400SS, and then the 95 catalog has AUS8. If they thought AUS8 was an improvement, I think they would have said something in the catalog (like they did with other steel changes over the years), but they didn't. This leads me to believe that their 400SS was either already AUS8 (which is equivalent to 440B), or the difference was too small to bother trying to glorify.

Also, in their description of AUS8 in the 95 catalog, they say "In contrast, at Cold Steel, we use AUS 8A a high carbon, low chromium steel that has proven, over the last 15 years, to be the ultimate compromise between toughness, strength, edge holding and resistance to corrosion". AUS8 had been around longer than 15 years at that point, but CS had started 15 years prior. Coincidence?

Regardless, even if they are technically different, like I said above, I really think that without a lab, no one is going to notice the difference in real world use.

 

[zakjak221]

Catalog is confusing when there's no way to distinguish tang stamps or years when they're the same & sheaths r the same,no marks on steel...

 

[knarfeng]

400SS or Aus8?​

Is there a way to tell the difference between these two?

AUS8 is a specific composition as it is a steel made by a single company, Aichi Steel in Japan

"400SS" is a non-specific designation. It could be any one of a half dozen different of alloys with different properties. And made by dozens of companies. Among the possible alloys are 410, 420, 420HC, 425, 440A, 440B, 440C. They all fall under the category of "400 series stainless steel"

Without a more specific description, the most likely guess would be that it was 420HC or 440A or pretty close thereto.
(If it had been 440C, they would have said so.)

AUS8 gets short shrift these days because too many companies cheaped out and ran it soft. For instance Ontario's spec for AUS8 was a 56HRC. But it works well if run at a hardness of 59 or better as Cold Steel runs it.

AUS8 has a higher carbon content and performs better than either 420HC or 440A. IMO the difference is noticeable in use.

 

[PeteyTwoPointOne]

I have a Lawman with the fatter handles in AUS8 and I'll never sell it...fantastic user!

 

[jlauffer]

AUS8 is a specific composition as it is a steel made by a single company, Aichi Steel in Japan

"400SS" is a non-specific designation. It could be any one of a half dozen different of alloys with different properties. And made by dozens of companies. Among the possible alloys are 410, 420, 420HC, 425, 440A, 440B, 440C. They all fall under the category of "400 series stainless steel"

Without a more specific description, the most likely guess would be that it was 420HC or 440A or pretty close thereto.
(If it had been 440C, they would have said so.)

AUS8 gets short shrift these days because too many companies cheaped out and ran it soft. For instance Ontario's spec for AUS8 was a 56HRC. But it works well if run at a hardness of 59 or better as Cold Steel runs it.

AUS8 has a higher carbon content and performs better than either 420HC or 440A. IMO the difference is noticeable in use.

Are there any known cases of 400SS being 440B, or would that have been considered good enough to call out by name?

 

[knarfeng]

Are there any known cases of 400SS being 440B, or would that have been considered good enough to call out by name?

The performance of 440B is significantly above that of 420HC and 440A, both of which are covered by the moniker "400 series."

I've never seen a case in which a knife company was using 440B and didn't say so. 440B is less commonly used in industry. Obtaining and processing it requires extra effort compared to 420HC or 440A. If it were being used, I'd expect the user to make it known.

 

[jlauffer]

The performance of 440B is significantly above that of 420HC and 440A, both of which are covered by the moniker "400 series."

I've never seen a case in which a knife company was using 440B and didn't say so. 440B is less commonly used in industry. Obtaining and processing it requires extra effort compared to 420HC or 440A. If it were being used, I'd expect the user to make it known.

Thanks Frank. Guessing that if you're gonna go thru the extra effort, might as well just use 440C? Is that why 440B isn't/wasn't very common?

Still find it odd though, if AUS8 was a big step up from the 400SS they were using, that they didn't promote the improvement. Unless they did, but in a form other than their catalog. Oh well, at this point we'll prolly never know for sure.

 

[knarfeng]

Thanks Frank. Guessing that if you're gonna go thru the extra effort, might as well just use 440C? Is that why 440B isn't/wasn't very common?

Still find it odd though, if AUS8 was a big step up from the 400SS they were using, that they didn't promote the improvement. Unless they did, but in a form other than their catalog. Oh well, at this point we'll prolly never know for sure.

Don't know for why. But I suspect you are correct.

Lost in the mists of time.

I've always considered AUS 8 to equate to "Stainless Carbon V". But the data Larrin has collected on the Chinese version of AUS8 show that AUS8 is superior in both toughness and edge retention to 1095, and Carbon V is not significantly different in performance from 1095 in those parameters. So, there's that rabbit hole to dive into, also.

Edited to add:
Larrin says that AUS8 was first made in the 1970's.

 

[Benjamin Liu]

Thanks Frank. Guessing that if you're gonna go thru the extra effort, might as well just use 440C? Is that why 440B isn't/wasn't very common?

Still find it odd though, if AUS8 was a big step up from the 400SS they were using, that they didn't promote the improvement. Unless they did, but in a form other than their catalog. Oh well, at this point we'll prolly never know for sure.

I think that at the time few knife buyers cared about steel type other than whether it was stainless or carbon.

Debating steel types really wasn't a popular activity until rec.knives and then Bladeforums.

I remember Cold Steel being bashed for using "only AUS 8" rather than ATS-34, and then a few years later people were bashing companies using "only ATS-34" rather than S30V, and this will probably continue.