Knife Metals

[45rook]

Hey guys I need some help about knife metals, can someone edge-u-cate me on the differences between CPM-440V, AUS6,8,10,VG-10, and GIN-1.

If you can please rate them in order of best steel and edge retention.

[Blade Santa Cruz]

Why ask to be spoon-fed when you can look it up yourself? Just click on Edge-u-cation and you'll find plenty of info on materials, including steel charts. < img src=http://kraziekurtis.50megs.com/samurai.gif = >

[45rook]

Blade Santa Cruz-
Its the good nature of the majority of the people in this forum that edge-u-cate others with less knowledge. Now first of all if you read my post correctly you would have known that I asked about steels for knifes not materials, which spyderco lists as materials they use for handles. I asked specifically about steels. If I knew more about the elements that are used to make the blades I would have a good understanding of that would be ideal and have a better understanding for the steel charts. I didnt ask for much, just baseline information on what steels are ideal for knifes and why. Also if you have read the posts that I have had you would know that I am new to the forum every one needs a little help knowlegde once in a while.
Hence: Give a man a fish and he eats today. Teach a man to fish and he can feed himself for the rest of his life.

To all others: a little help would go a long way.

[sc_rebel1957]

hi 45. with limited knowledge of some of the steels u mentioned (440 V) being the 1 i know the least about.here goes..from what ive seen and rad about 440v it supposed to be very abrasion resistant and is fairly stainless. Ive not had a chance to use this steel yet, but i did read where it is sometimes brittle and would chip very easy hitting bone, metal and such, but thats also why it stays sharp longer! most figues ive seen put it at 58-60 on the rockwell scale. AUS-8A is used by a ton of different makers.57-59 on the rc scale..holds an edge great and is quiet stainless also..its easier to sharpen than more exotic metals making it a good choice for an all around EDC. AUS-10 i know nothing about. Now we get to the best thing goin since sliced bread.IMO i cant imagine a better material for knife blades than VG-10, i have yet to dull a blade enough for it to need sharpening its amazing how long this steel keeps a razors edge.and outta all the 1s you asked about this is the mac daddy of steels GIN-1 and GIN-2 are the same thing spyderco used it on the NATIVE and it also holds a good edge 57-59 rc, ive used it diving in salt water and forgot it til the next day and never saw a spot of rust I do find it harder to sharpen but once u get it sharp it doent take much to keep it that way....Im sure theres more people in here that can answer ur questions better than me but maybe this helps some.....Ron

[Clay Kesting]

45rook,

Check out Joe Talmadge's <a href="http://www.bladeforums.com/features/faqsteel.shtml">Steel FAQ</a> at BladeForums.com. The Vanadium added to the AUS series steels and VG-10 seems to encourage the formation of very fine carbides. This in turn lets these steels take a super edge. CPM440V also has a very fine grain structure due to the <a href="http://www.crucibleservice.com/">crucible</a> method of manufacture.

Clay

Life's too short to waste on instant coffee.

Edited by - Clay Kesting on 5/20/2002 5:08:38 AM

[Sword and Shield]

They're all decent steels, at the very least, but there are good and bad points.

AUS6/AUS8- Easy to sharpen, takes a very good edge. Con- Doesn't hold an edge as well as the steels listed below.

AUS10- Slightly more difficult to sharpen than 6/8, but still easy. Takes a finer edge and holds it accordingly well.

GIN1- A "middle ground" steel, it holds an edge better than AUS10, but not as well as VG10. Sharpening difficulty is between AUS10 and VG as well.

VG10- Excellent all-around steel. Holds an edge extremely well, takes a very fine edge. This requires a little sharpening skill, but is not especially difficult.
Pro- Most "Stainless" of the group by a large margin.

CPM440V(S60V)- The best edge holding on the list, and conversely the hardest to sharpen. Has a slight tendency to form a wire, but can be overcome with careful technique.
Slight con- Is a high-carbon steel, can pit if left in extreme conditions.

Best steel- I can sharpen anything, so S60V is my favorite. For someone just starting out, VG10 is an excellent balance between ease of sharpening and edge retention.

Keepin' it real...real sharp, that is.

[Joe Talmadge]

I generally encourage people not to think in terms of "best steel". Many steels have tradeoffs versus each other, so "best" depends on the particular use the knife is going to be put to, the demands of the particular knife design and edge geometry, the heat treat, etc. It's better to try to just understand the general properties of each steel, and then make value judgements like "best" based on what you're doing.

S and S provided a great starting point. Note that 440V (S60V) is the one he likes best, and it's also a fantastic steel to illustrate the problems with "best steel". The first thing to remember is that wear resistance does not mean edge holding. 440V is very wear resistant due to an abundance of well-distributed, super hard vanadium carbides. And for light cutting, wear resistance pretty much determines edge holding. However, for heavier duty cutting, the main problem for edge holding can often be indenting, rolling, or chipping, in which case strength and toughness become important players in the edge holding formula.

440V is relatively brittle. So if it's left hard -- and therefore, strong -- it can be brittle and chip out under hard use. If this happens, you can leave the edge extra-thick, in which case performance will stink, or you can leave a performance edge but end up with micro-chipping being the primary determiner of edge retention. In other words, you've got that great 440V wear resistance (and difficulty of sharpening), but chipping ends up being more important than wear resistance for edge holding.

So, with that being a problem, you can do with Spyderco did, which is drastically lower the hardness of their 440V. This leaves an edge that's tough enough that wear resistance once again becomes more important than toughness in the edge holding equation, so you're getting the best out of 440V again. However, at such low hardness, the steel becomes weak, so for harder use, rolling and indenting can become real problems, and once again overshadow wear resistance. Again, you can leave the edge thicker for more strength while sacrificing performance, or you can leave a more performance-oriented edge and risk problems with the strength.

Whether this is actually a real problem is up to the way you use your knife. Many people have Spyderco 440V blades and never see an indent. On the other hand, some people also see indents and rolling, and see the edge holding being subpar (probably because of the nature of their usage). For these folks, going with VG-10, which is tough enough that it can be left hard and strong, will be a better choice. <b>And for those people, they'll see better edge holding from the VG-10 blade, even though 440V has better wear resistance. </b>

That's also why you see VG-10 being used for bigger fixed blades, but not 440V. Big blades and choppers need to be both strong and tough at the same time. With 440V, you can't get both at the same time. With VG-10, you can. Of course, there's limits to even that. For serious heavy-duty chopper, even VG-10 doesn't cut it. Anyway, back to my <b>main point </b> . By understanding the disparate steel properties, rather than just memorizing &quot;bad, good, better, best&quot;, you'll be able to gauge the usefulness of a particular steel to a particular application much more accurately.

Joe

Edited by - Joe Talmadge on 5/21/2002 11:50:58 AM

Edited by - Joe Talmadge on 5/21/2002 12:09:10 PM

[Blade Santa Cruz]

Joe,

Thanks for an intelligent summation that puts things in perspective. There was and may still be an interesting discussion on the Blade Forums on S30V and whether certain makers are developing the full potential of the material at 58-59 RC for folding knives.

For this discussion, I find it interesting that, given the caveats in your post, Spyderco chose 440V for its Military model. This is a good size, albeit not huge (4 in. blade) knife that is meant to see plenty of use and abuse. I carry one as my EDC and love the knife. However, like S&amp;S, I can sharpen pretty much anything, so 440V is no problem.

The knife has done plenty of hard cutting, although limited to appropriate tasks for a pocket knife, not an axe, crowbar or screwdriver. But the whole discussion points out that not only the steel composition, but the heat treating, blade design, intended uses and skill/experience of the user can greatly influence one's choice of &quot;best&quot; steel.

[jjmc2001]

Thanks guys. That was a great summation of some of the various steels. I have a Native in 440V that is an EDC, used but not abused. With a 204 I can get it very sharp but I have had it chip in a couple of spots when the blade bumped a rock as I was making a quick slice. Nothing serious but it kind of suprised me as it did not strike the surface very hard just bumped it in a straight vertical motion. The 204 fixed it right up with a little work.

[Joe Talmadge]

BSC: Yes indeed, interesting that it's 440V on the Military (is there still an ATS-34 option as well?). I *think* Spyderco was the first to put 440V in production blades. It was a move by a leader to get interesting new steel technology into the hands of users at production prices.

I do know that Spyderco's 440V was originally much harder, but that they softened it up a few points, and claimed that edge retention was not affected at all at the lower hardness, while sharpenability was improved. I'm guessing that part of the reason edge retention was still good at the lower hardness is because at the higher hardness, the edge was micro-chipping out a bit.

With current 440V, as I said above, many users do not see any problems with strength, they just see an edge that lasts forever, although sharpening is still not a joy. So for many users, 440V seems to be a fantastic solution. However, some users definitely see problems, both with indenting, and with edge retention generally. I believe that if a user is seeing bad edge holding with Spyderco's 440V, and they're sure they've polished off the burr correctly, the edge holding problems are probably being cause by a weak edge that turns too easily. The thinner you make your Military's edge, and the more force you put on the edge, the more you'll see the effect. For these types of users, ATS-34 would have been a better choice, since it's easier to sharpen and stronger.

jjmc: Can you confirm again that what you saw were *chips* in your edge? Are you sure the edge wasn't just indented? Was this with the original-production high-hardness 440V, or the newer 55-56 Rc 440V? Thanks!

Joe

[jjmc2001]

Joe T
My Native (w/CPM 440V) had a series of 4 or 5 small indents in the edge that appeared to be chips but could have just been indents. I am looking at it now and they are all but gone after a couple of sessions on the 204.
Prior to the problem the edge was sharpened on the 204 at 40 degrees and had not been used since sharpening. The blade was pressed down pretty hard(unintentionally) on exposed aggregate concrete and then I noticed the scarring. Actually looked like a min-serration. With my aging eyesight it was hard to tell exactly what had happened.
Again no problem fixing it right up on the 204. I have used this Native frequently for all kinds of miscellaneous household &amp; yard cutting and it holds an edge as well as any blade I have ever had.
I have numerous other Spydercos but I keep reaching for the Native. Light with a very strong feel for its size. Typical for A Spyderco.
Quick story: I used it to slice the head off a Copperhead recently and it cut it so cleanly I thing we could have sown it back together. I don't want to hear from any PETA snake lovers. Any venomous reptile that ventures into my yard will get cut or shot (or both).

[dialex]

I don't know much about steel, but I do know that carbon is essential; more carbon means harder steel, but also less elasticity. It can break easily. So it is not suitable for long blades, as smatchets or swords. On the other hand, less carbon (as in AUS steels) means more resistance to corrosion, which could be more useful in some environments.

[boxer93]

Joe T and all,
Thanks for all the info. I have 2 questions. Does the chipping or indents occur more or less from PE or SE?
Second ? for Joe. If you had your choice of steel for a hard use knife which would you choose. I noticed you mentioned the ATS-34. I was checking my EDC and noticed my Ti Salsa is ATS-34.
Thanks
Chris

Be Excellent to each other.

[Daga]

What do you think about ATS 55 ?

[Joe Talmadge]

boxer: if we're talking about folders and I'm looking for stainless, BG-42 and 420V are my faves. If I'm willing sacrifice a little stain resistance, D-2 can be beter still -- it won't hold an edge like 420V, but it's much tougher and can be hardened to high strength, so it can support a nice thin high-performance edge better. For my carry folders, I don't like to have to do too much maintenance, so I don't necessarily look at non-stainless steels beyond D-2 unless they have a coating. And since I dislike coatings, I'll stop here. Actually, I should mention one last thing: I haven't tried S30V yet, but if it lives up to the reports I'm hearing from knifemakers, it will be the best choice hands-down, even over D-2. The fact that CRK has gone to S30V means a lot, though I like to try it out firsthand before I draw any conclusions.

In any case, there are some important keys here. First is the heat treatment: it's not just that it has to be done well, but I want it to be tuned for a folder's needs, if I'm buying it for a folder. Secondly is my sharpening plan: if I'm not taking advantage of the steel's properties in my sharpening plan, then I will absolutely not see the level of performance gain that I could. So if you're just always putting 20-degree bevels (say) on your folders, and not tuning that down for better steels, then there is no reason to obsess over what the exact steel used is. Either take advantage of a high-performance steel in your sharpening plan, or don't worry too much about the steel.

Lastly, this does all depend on what &quot;hard use&quot; means to you. In a folder, I always try to put the very thinnest highest-performance edge the blade can take. Hard use tends to mean that I want to be able to torque the edge and push it hard into things, without indenting, rolling, or chipping, so edge strength and torquing toughness are a must. With big fixed blades, impacts from chopping have to be considered, too. And frankly for a big fixed blade, ease of sharpening becomes more important to me -- while I can get anything sharp, I get impatient sharpening an 8&quot; blade if the steel is really sharpening-resistant.


Joe

Edited by - Joe Talmadge on 5/24/2002 10:00:15 AM

Edited by - Joe Talmadge on 5/24/2002 10:02:56 AM

[boxer93]

Thanks Joe. How did you get to know so much about all these steels? Do you run a steel mill <img src="smile.gif" width=15 height=15 align=middle border=0>

Chris

Be Excellent to each other.

[Joe Talmadge]

Before I had kids, I apparently had way too much time on my hands <img src="smile.gif" width=15 height=15 align=middle border=0>

The real story is, back before the world wide web, the only place to talk knives was rec.knives. I think this was in the late '80s, if I remember right. We on rec.knives bemoaned the fact that there were no FAQs to teach the newbies. After a year or so of this, I decided that I was going to write the FAQs myself. I spent the next few years reading everything I could, talking to knifemakers, and buying tons of knives and testing them head-to-head against each other to get firsthand proof of the differences steels, edge geometry, etc, made. Firsthand testing turned out to be important, since I found many major or minor inaccuracies -- more like urban legends that just kept getting repeated -- that were repeated among knife writers. The rec.knives FAQs, which you can find in many places including rec.knives, bladeforums, etc., were the result. And that in turn generated a lot of interest and feedback from some really knowledgeable people. It also generated arguments which often sent me back in the garage to re-test the claims I'd made, and adjust whenever I felt there were inaccuracies.

I don't have the time I used to, so on some of the newer steels, like S30V, I'm still relying on 2nd-hand reports rather than doing any direct testing myself. Someday I'll get around to being able to test the newer stuff for myself.

Joe

[boxer93]

Well I'd say you learned the subject very well. I know what is like to lose all that time when kids come around. I expect in another 10 years I'll get back to doing more of the things I want to.
Chris

Be Excellent to each other.