Knife Metal

[Chief]

I have a question about the stainless steels used in knife blades.  I purchased some knife blades advertised as being 440-C.  Later I saw some print on the blades I bought that advertise 440-C (6-A).  I questioned the seller about what the (6-A) meant, was it 440-C or really AUS 6A.  I'm certainly not an expert but 440-C and AUS 6A are certainly two different steels from what I read.  The seller said the blades were not AUS 6A.  He said they were Japanese 6-A which is equivallent to 440-C.  I want to believe that's true, but a quick search of the internet doesn't verify the statement.   In fact, I found out AUS 6A is a Japanese metal itself.  I suppose it doesn't matter in my case but I really wanted 440-C stainless.  Do any of you folks know anything about these metals and if the (6-A) really is equivalent to (440-C)?  Thanks.  :?

[Joel]

The American(AISI) term for Japanese AUS-6(A), also seen as just 6A is 440A.  AUS-8(A), also 8A, is 440B,
The Japanese term for 440C is AUS-10A,also seen as 10A . These steels are roughly equivlant to each other, however all three Japanese differ from the American ones by having a small amount of Vanadium added to them, which 440A,B,C lack, which should make them slightly better steels as far as toughness and edge holding go. It all depends on what kind of heattreatment they're given.  The other major difference between them is the carbon content.  440A(AUS-6A) runs .60-.75%, 440B(AUS-8A) runs .75-.95% and 440C(AUS-10A)runs .95-1.2%.  AUS-10 has slightly less chromium then the roughly equivlant 440C.  Basically what that all boils down to is that as you move up a letter(or number) you're getting a better steel(always assuming proper heattreat).  Also, with the addition of Vanadium, each of the Japanese steels has a better composition than its roughly American equivlant.  Hope this ain't too confusing.

[Chief]

Thanks Joel,
Appreciate the info.  Looks like the blades I bought should probably be, more accurately, described as 440A than 440C.  Oh well, I guess it's an effective marketing stategy, got my money. Thanks.

[ButlerFord45]

Chief, give this a try  http://agrussell.com/steel/index.html




Butler Ford

[Chief]

Thanks ButlerFord45,
The chart spells it all out.
Chief

[feyxla]

Considering the Spyderco Native SS, Coldsteel Gunsight, or Boker Zeta.

The Boker has a ceramic blade. are they any good compared to SS blades.

All of coldsteels models are AUS-8A, the Spyderco is AUS-10A.
Which one should I go for?

[Joel]

Ceramic blades have two disadvantages, at least as I look at them.  One, they're brittle, i.e. they don't bend much atall without snapping. Two, they don't stay sharp forever, although if you only use them occasionally it may seem so.  Once dulled, they have to be returned to the factory to be re-sharpened, which if memory serves me, runs about $15.00.

Assuming each steel is given it's optimum heat treat, then AUS-10A should have a bit of an advantage over 8A in edge holding.  Both steels are popular, which means either of them probably work well enough.  If the blades are beadblasted then be prepared for either to rust unless given a preventative.  There was a long thread some time ago over at bladeforums.com about combating rust on beadblasted AUS series steels.

[rd2903]

Have never heard of the steel you mentioned, I'm a maker and I use lots of 440C, my customers are extremely happy with its edge holding quality in the hunting knives I make.  I let a friend and fellow maker temper them for me, I find that 58-59 rockwell works the best.  Secret to keeping it sharp is not to over sharpen it.  When it will stick on your nail quit.  I offer lifetime sharpening,  but seldom ever get them back.  I have worked some 1095, and a variety of damascus.  But for the Gulfcoast with all of the humidity 440C is my favorite.

[Joel]

We've some things in common: we're both retired military(navy in my case) and we both started making knives about the same times.  I started out using 440C, and I liked it, but some of my pig hunting customers didn't care for the edge holding(Rc of 58) when doing multiple pigs.  These guys were fanatics.  Switched to 154CM/ATS-34 and that cured their complaints.  My personal favorite is BG-42 although I'm fond of D-2 also,  It'll hold an edge better than 154, but not as good as bG-42.  I'm currently building my first knife out of A-2 high carbon.  Next on my list to try is S-30V, which analyzes like a souped up BG-42.
There's a number of steels out there that are available only to the big knife manufacturers, because they can only be bought in humungous rolls or sheets.  The AUS series, VG-10(a darned good steel), ATS-55, 425M are one's that come to mind.

[rd2903]

Navy for me too, Seabee CPO  I prefer 440C, I have used ats34 but the expense keeps me from using too much.  My buddy hog hunt in florida I'm going on a deer hunt to W.VA later this year and plan to give hime one.  So we'll see.  Nice to hear from another veteran

[Joel]

Retired Senior Chief('84).  Where do you get your steel from?  I've been using Admiral Steel for years.  www.admiralsteel.com.  Ats-34/154Cm runs about a dollar more per 18", depending on the size you get.  Minimum $25.00 order, but you get more steel than from Sheffield/TKS etc.  Thing I like about 440C is the way it polishes.  Doesn't orange peel like 34 or 154.  Good luck on your deer hunt.

[rd2903]

CPO retired in 96, I buy most of my stuff from admiral.  Some I have picked up from sheffield and the like.  I have alot of fun at it.  I work some damascus, thunderforge.  I'm working a big 1/4 inch piece  locally made now for a huge bowie, will put fossil walrus on it, with silver trimmings.  I personally like the edge holding quality of 440C, but everybody tells me that ats 34 holds a better edge.  I'm going to send a knife of mine to a buddy that hog hunts he claims that, that will be the ultimate test.  Later