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AUS-8 vs AUS-8A

Discussion in 'Knife Reviews & Testing' started by DocNightfall, May 4, 2009.

  1. DocNightfall

    DocNightfall

    268
    Nov 20, 2006
    I stumbled upon a reference written by a knife maker named Terry Primos that says the AUS-8 and 8A are two different compositions and not interchangeable. AUS-8A seems to be an intermediate grade between AUS-8 and AUS-10. 8A has more carbon and has molybdenum and tungsten added.
    http://www.knifeseek.com/workshop/tut_composition_primos.shtml

    An article that also makes a distinction between the two steels.
    http://www.gunblast.com/Fryxell_KnifeSteels.htm

    Here's a Chinese forum thread with some text in Polish (huh?) that gives compositions of AUS-8 and 8A as well as some guy saying that AUS-8 is subjectively equivalent to 440A/B, and AUS-8A is equivalent to ATS-34.
    http://www.knifriend.com/viewthread.php?tid=28451&page=3

    I'll copy the two compositions here--

    AUS8
    C =0.75
    Mn=1.0
    Si=1.0
    Cr=14.5
    Ni=0.49
    Mo=n/a
    V =0.25
    W =n/a

    AUS8A
    C =0.90-1.0
    Mn=1.0
    Si=1.0
    Cr=14.0
    Ni=0.50
    Mo=0.10-0.30
    V =0.10-0.20
    W =0.40

    Can anyone verify this with the manufacturer of these steels? Has anyone here used both 8 and 8A and noticed any difference in performance?
     
  2. Vicarious Reality

    Vicarious Reality

    Apr 9, 2008
    o_O

    Maybe that's why i like Cold Steels Aus8(a) so much?
     
  3. DocNightfall

    DocNightfall

    268
    Nov 20, 2006
    Maybe.

    According to manufacturers' websites, AUS-8A is used by Cold Steel, KA-BAR, Kershaw and Blackhawk knives.

    AUS-8 is used by Benchmade, Spyderco, CRKT, SOG and AG Russell.
     
  4. DocNightfall

    DocNightfall

    268
    Nov 20, 2006
    The first link above also shows that AUS-6 is different from AUS-6A.
     
  5. 3Guardsmen

    3Guardsmen

    Mar 16, 2005
    "AUS-8" and "8A" both refer to the same steel, made by Aichi Foundry in Japan. It's like how "Gin-1" and "G-2" refer to the same steel. Can you name a company that actually puts "AUS-8A" in their ad copy or product specs? I can't. It's either AUS-8 or 8A, not AUS-8A. I have heard of AUS-8W, which is AUS-8 (or 8A) with Tungsten added.

    FWIW, I'll take Sal Glesser's word over Terry Primos'.;)

    Regards,
    3G
     
  6. DocNightfall

    DocNightfall

    268
    Nov 20, 2006
    Cold Steel, KA-BAR Kershaw and Blackhawk all say "AUS-8A" on their published product specs and never make any mention of AUS-8.

    The reverse is true for the product specs of Benchmade, Spyderco, CRKT, SOG and AG Russell.
     
  7. 3Guardsmen

    3Guardsmen

    Mar 16, 2005
    I'm pretty sure they meant AUS-6 and AUS-6M (not AUS-6A), with AUS-6M being a steel CRKT used for a while.

    After checking that first link you posted, and reading what I've read, I'd be willing to bet that the "AUS-8A" is really AUS-8W, and the "AUS-6A" is really AUS-6M. Just typos or mistakes would be my guess.;)

    Regards,
    3G
     
  8. 3Guardsmen

    3Guardsmen

    Mar 16, 2005
    That's funny, because Cold Steel calls the steel they use "8A" verbally in their "Proof" videos.
     
  9. DocNightfall

    DocNightfall

    268
    Nov 20, 2006
    I don't understand what you're getting at. 8A obviously refers to AUS-8A, which does not in any way discount the possibility that AUS-8 without the A may be something else entirely.
     
    Last edited: May 4, 2009
  10. 3Guardsmen

    3Guardsmen

    Mar 16, 2005
    I was speaking of Cold Steel referring to their AUS-8 simply as "8A," which is just another term for AUS-8, and not AUS-8A, which would be redundant. AUS-8 and 8A are not different steels. Sal Glesser knows what he's talking about!

    Regards,
    3G
     
  11. DocNightfall

    DocNightfall

    268
    Nov 20, 2006
    There is a steel named just 8A without the AUS that is also made in Japan, but it isn't a martensitic steel-- unusable for knives. http://www.kaker.com/std/ctt/html/364.html

    I've emailed Aichi to inquire. I am doubtful as to whether they will answer, but it's worth a shot.
     
  12. DocNightfall

    DocNightfall

    268
    Nov 20, 2006
    Indeed. So it must follow that Mr. Primos, Mr. Fryxell and Mr. Clements (http://www.knifemakersdatabase.com/...MD/KnifemakingBladeSteelCompositionChart.html) do not know what they are talking about?

    I know what you meant. BUT, Cold Steel's website makes no mention at all of AUS-8 without an A. Thus if the Cold Steel proof videos mention "8A" then they are obviously referring to AUS-8A (which they do mention, repeatedly), which does not advance your argument that AUS-8 and AUS-8A are the same.

    I do, however, accept Sal Glesser's authority as evidence that shifts the balance slightly in favor of the idea that they could be the same steel. But I'm still undecided.
     
    Last edited: May 4, 2009
  13. 3Guardsmen

    3Guardsmen

    Mar 16, 2005
    It sure gets confusing, doesn't it! Lol:D Hopefully Aichi will reply, or perhaps Sal or one of the other knife company reps will see this thread and reply. Like I said before though, I'd be willing to bet that site's (Primos') just had the wrong designations written. It can certainly happen! While checking A.G. Russell's Steel Guide a moment ago, I noticed he has 0170-6 (aka. Carbon V and 50100-B) listed as a Stainless Steel, with 14% Chromium.:D Mistakes are human!

    Regards,
    3G
     
  14. 3Guardsmen

    3Guardsmen

    Mar 16, 2005
    Well, DocNightFall, that steel chart is almost an identical copy of the one you posted earlier:

    Both of those charts have the same steels listed. They even have the same mistake listed for what they call "CPM T440V" (the "T" stands for Trademark, in case you were wondering). The second chart you listed has "CPM S60V" listed as well as "CPM 440V," which are the same, and they have slightly different specs listed for it lol:p. If they have one mistake in there, and they have more than that, it stands to reason they could have others!;)
     
    Last edited: May 4, 2009
  15. DocNightfall

    DocNightfall

    268
    Nov 20, 2006
    The second list is far more comprehensive and the order is also different. The first one does have a typo with CPM440V but the second one doesn't. They were certainly not thoughtlessly copy-pasted from one another.
     
  16. 3Guardsmen

    3Guardsmen

    Mar 16, 2005
    You're absolutely right about the second one being far more comprehensive than the first. However, you're wrong about the second one not having the typo. Here's a 'cut-n-paste' from that second chart you linked to:

    "CPM 2.15-2.2 17 - 17.5 --- .5 .5 --- --- .5 --- --- 5.5 -5.75

    T440V
    "

    Now here's the same exact steel, listed with different specs on the same chart.

    "CPM 2.15 17 --- .4 .4 --- --- .4 --- --- 5.5

    S60V
    "

    Like I was saying, where you find one mistake, you'll find others.

    Regards,
    3G
     
  17. DocNightfall

    DocNightfall

    268
    Nov 20, 2006
    Yep, and I'm trying to figure out which human(s) to believe.
     
  18. 3Guardsmen

    3Guardsmen

    Mar 16, 2005
    Well, I'll just say this then. Sal (Founder of Spyderco) has been purchasing AUS-8 (or 8A) from Aichi Foundry for use in his knives since 1980, so if he says the steels are one in the same, they're one in the same.:thumbup:

    Regards,
    3G
     
  19. DocNightfall

    DocNightfall

    268
    Nov 20, 2006
    What bothers me is that Sal Glesser seems to be the only one directly stating that AUS-8 and AUS-8A are the same steel. Cliff Stamp does, too, as do many others but they all seem to cite Mr. Glesser or Spyderco as the source.

    Yes, I know that just because there is just one of him doesn't mean he is wrong, but I still cannot commit to one side or another based on only the information available at the moment.

    I didn't start this thread to prove a point, but to raise questions. I hope more people can add to this discussion, not necessarily Mr. Glesser himself but hopefully someone who has worked closely with Aichi.
     
  20. 3Guardsmen

    3Guardsmen

    Mar 16, 2005
    I totally get what you're after, and I too would like to see someone from Aichi put this matter to rest. I remember having seen a thread (pretty sure it was here on these forums) where this was discussed before, and somebody from a foundry in Japan did comment, but I can't find it for the life of me.:grumpy:

    I will offer one other observation that does pertain to this discussion. From what I've seen, the numbers in the names of Japanese steels tend to change as the amount of carbon and the quality goes up. A good example would be that you have VG-1, VG-2, all the way up to VG-10. The same is true for the AUS steels. You have AUS-4 (I never heard of it prior to CRKT), AUS-6, AUS-8, and AUS-10. When a steel is modified with an additional alloying element, a letter is usually added after the number in that steel's name, such as in the case of AUS-6M and AUS-8W. I find it strange that Aichi would add .20 % carbon to AUS-8 and still call it AUS-8. I would think they'd opt to use another name, like AUS-12, since AUS-10 is already taken.

    Regards,
    3G
     

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