s30v

[FernetBranca]

Gentlemen,

I especially joined up to congratulate you all on a terrific and highly informative thread. In particular, I consider the contributions of Cliff Stamp and Jerry Hasson most valuable.

Cliff: Am I correct in my understanding that you argue that:

On very low angled edges, the large carbides present in the higher carbon content stainless steels tend to fall out, undermining the integrity of the edge, which not only brings about lowered abrasion resistance but also the creation of stress concentrators that can initiate chipping. So, for lown angle edges we would all be better off with low carbide steels.

If the above is correct, then what we really ought to be looking at is the lowest edge bevel angle that a high carbide stainless steel will work with.


Jerry: What edge bevel angles did you use in your nail cutting experiments?

Regards
FernetBranca

 

[gator68]

Sorry, but I only accept the anecdotal results of such unscientific methods when performed by qualified carpenters


Sorry, couldn't resist ...

Naw, annecdotal evidence should only be accepted when either 1) it confirms what you already know or 2) it helps promote the latest, greatest steel.

BTW, kudos to Hardheart for putting his knives to the test.

 

[Cliff Stamp]

Maker has viewpoint/label Z on such knives.

The viewpoints come from the PROPERTIES. It is the PROPERTIES that are being contested.

One attempt with a Schrade Century swiss army knife knockoff, made in Germany. Nondescript stainless, I had it scraping hair sharp before this 'test'. Cut through the nail in half a dozen blows. Almost no visible damage to the very edge itself, it appears straight when viewed from profile; but the entire section that cut through the nail is a single ripple, about 2 mm long and 1mm high, putting it into the primary grind. You have to catch it in the light, but the mirror-polished blade really shows it off.

THere you go, low carbide steel, exactly what I said

On very low angled edges, the large carbides present in the higher carbon content stainless steels tend to fall out, undermining the integrity of the edge, which not only brings about lowered abrasion resistance but also the creation of stress concentrators that can initiate chipping. So, for lown angle edges we would all be better off with low carbide steels.

Exactly right.

If the above is correct, then what we really ought to be looking at is the lowest edge bevel angle that a high carbide stainless steel will work with.

Exactly right. Landes has studied this in some detail. Now the critical point is that when you increase the angle then the cutting ability is lowered and the cutting lifetime. Just compare the 420HC to the higher carbide steels when the angle is higher. This is a GENERAL PATTERN not an isolated case, Swaim studied it extensively ten years ago with many different steels as did Johnston. Landes MEASURED it in detail as did others before him.

Naw, annecdotal evidence should only be accepted when either 1) it confirms what you already know or 2) it helps promote the latest, greatest steel.

THat has to be a coincidence, knife makers would never be biased against the products they are selling, that is just absurd. Next thing you are telling me is that not all people in jail are guilty.

-Cliff

 

[hardheart]

BTW, kudos to Hardheart for putting his knives to the test.

the things I'll do when I get bored

I don't know if I was checking toughness or strength at the edge. There would be a big moment of impact at the spine, but there was constant contact between the edge and nail, I don't know how that works out.

 

[Ebbtide]

THE PROPERTIES!

Acceptance or rejection of said properties are based on the particular maker's market share.

A mass producer of knives will accept properties that a custom maker can afford to reject.

Niether is out to make the ultimate/perfect knife. They are out to satisfy their share of the market (and hopefully make enough $ to stay in business).

 

[knarfeng]

Exactly right. Landes has studied this in some detail. Now the critical point is that when you increase the angle then the cutting ability is lowered and the cutting lifetime. Just compare the 420HC to the higher carbide steels when the angle is higher. This is a GENERAL PATTERN not an isolated case, Swaim studied it extensively ten years ago with many different steels as did Johnston. Landes MEASURED it in detail as did others before him.-Cliff

Cliff,
Earlier in this thread, you said that you would expect a 20° S30V edge to be stable because of the geometry, ie there would be enough steel around the carbides to support them.

Please clarify. Was that 20° on a side? Or was it 20° inclusive?

Sorry for the repetitive question. I'm just trying to understand the phenomenon.

 

[Nimravus Nut]

You seem to have agreed with the whole point of this thread, which is constantly getting lost. The application here was for a large chopper in S30V. Large choppers need edge bevels easily in excess of 20 degrees.

Jerry, I do believe there is so much being discussed here, people do get side tracked, besides it was you that brought up the question about 440a being better at edge holding than 440c.

I do not agree with Cliff about 440a being better in edge holding than 440c, but there are cutting applications that may include side loading that causes 440c edge to rip out.

After reviewing some of your arguments, I do believe there is a generalization about S30v. S30v is a carefully made powder steel that requires high level of cleanliness compared to how most traditional steels are manufactured. So in regard to the scrutiny level of production, isn't it true that S30v requires a hightened level of heat treat process? And from majority of the users here, there is a lot of people complaining S30v chipping out than those who uses VG-10, 440c, infi, or 154cm.

Maybe, Jerry, you are the only one that got the heat treat right on S30v, because I don't ever come across anyone that complains about your knives chipping out. But then you also wouldn't disclose your heat treat process to another maker, right? I then assume, if most other makers can't get the heat treat right on S30v suitable for large chopper, then I can say that it is unsuitable for S30v to be used as large chopper unless you made it.

The general point I'm trying to make is that S30v is hard to heat treat and it's even harder to get it right to make it tough enough for a large chopper. Sticking to the context, there are other stainless more suitable for a large chopper for a much lower cost. For example, Aus8, VG-10, D2, even 440c are much better for choppers if you don't want it to chip and not wanting to pay $500+ for a custom "use" knife.

 

[Habeas Corpus]

Was that 20° on a side? Or was it 20° inclusive?

In my experience S30V works best with something like 15 to 20 degrees on each side. If you want to be on the safe side you need about 20 degrees per side.

Hans

 

[FernetBranca]

Cliff,

I am inclined to agree with you and will add that I think we had been hoodwinked with the stainless steel cutlery revolution. I am also inclined to agree with Verhoeven that the best all round satinless steel for knives is 12C27 or something like it.

Back in the days when carbon steel ruled, I always sharpened my knives to around 13 degrees per side and never ever had I experienced edge failure or micro chipping despite some pretty hard usage. Yet when the super stainless steels became the norm I was forced to increase the edge angle to 18 degrees per side and even then I experienced the occasional chipping when cutting into harder materials.

I really think that all these years we have been going backwards and if a steel like12C27 is not up to the mark, then we would all be better served with something like 1090 given a protective plating akin to what Gerber did in the 60s with their then new range of hard chrome plated kitchen and skinning knives.

Regards
FernetBranca

 

[ginaz]

and that is what those in the industry cannot abide, is that the newer steels are not "progress". technology and all it entails is our modern idol. we imagine ourselves to be at the absolute pinnacle of knowledge and ability and the possibility that a simpler way (be it steel or way of life) could be a better way is anathema to the great god of progress who commands that we march ever forward and disdain all that has come before.

 

[zenheretic]

Cliff,

I am inclined to agree with you and will add that I think we had been hoodwinked with the stainless steel cutlery revolution. I am also inclined to agree with Verhoeven that the best all round satinless steel for knives is 12C27 or something like it.

Regards
FernetBranca

Hoodwinked? The grand crafty cutlery conspiracy? Did you forgot the holy trinity tradeoff of steel? Who forced you to buy Stainless?

Reality is the majority of people who buy knives don't give a flaring red monkey's posterior what the steel is, they just want it to cut...and in the last generation to not rust. Stainless provides that. People want it so makers make it. Poor internet nerds stumble upon bladeforums and start worrying if 5 degrees per edge will make a difference when they cut while in reality they never cut more than cardboard, or they worry if mineral oil or militec is the best lube for their SS on the month.

It is only the handful of metal heads parsing the minute differences between carbon and other impurities that even really care. The majority couldn't tell the difference.

No matter how many steel data sheets you memorize. No matter how many knives you beat with a hammer. The reality is there are far to many variables to make much of any conclusive claims. If nothing else does it, the ever mysterious proprietary heat treat will forever muddy the waters.

Hoodwinked. This thread is great.

 

[FernetBranca]

zenheretic,

You know what? I totally agree with your assessment.

All the same, I find it ridiculously ironical that a cheap anachronism like an Opinel, consistently out cuts the most sophisticated and expensive modern tactical folders. This is more in hope and exasperation, but surely the trend setters of the industry could have taken us in a different direction, away from the current breed of carbided stainless steels.

It is a shame that now, when at long last we can buy knives that are truly marvels of engineering, of a quality unimaginable even as recently as 20yrs ago, they should be downgraded by the necessity of having to sharpen them with edges so thick and obtuse that their cutting performance is way behind all their other attributes on account of the unsuitable but overstated steels used. IMHO there are better ways around the corrosion problem, which incidentally I consider quite real and valid, than the use of high carbon stainless steels.

Anyway, I applaud Cliff and all the others like Verehoven who have pushed this issue and do their best to educate the rest of us, the consumer who pays for the goods and ultimately keep the cutlers in business.

Regards
FernetBranca

 

[zenheretic]

zenheretic,

You know what? I totally agree with your assessment.

All the same, I find it ridiculously ironical that a cheap anachronism like an Opinel, consistently out cuts the most sophisticated and expensive modern tactical folders. This is more in hope and exasperation, but surely the trend setters of the industry could have taken us in a different direction, away from the current breed of carbided stainless steels.
...snip...
Regards
FernetBranca

Well if anyone wanted to accuse anyone of hype; the tactical folder would be a great place to start pointing fingers at many folks.

Sure good ole tool steel is great for cutting. But those durned lazy normal buyers (that's me) really get peeved at rust. So off we go to the races trying to find a steel that doesn't rust.

Then D'oh! Suddenly it is hard to sharpen, now those durned lazy normal buyers (that's me) get really peeved that their unskilled sharpening skills don't work worth a darn. So off we go the the races trying to a steel that doesn't rust and is easy to sharpen.

Then Gosh Darn! Suddenly it chips when you look at edge with a frown or a wink. So it is off to the races trying to find a steel that doesn't rust, is easy to sharpen, and doesn't chip....

Along the way, the wealth of knowledge expands. Bits of reality bump into each other both perhaps true, but seeming to our eyes to clash with disagreement that both realities are possible.

This isn't a static industry, in fact it is an exciting time to be involved or just watch from the sidelines. Ahh progress, like growning, hurts.

Pity the egos.

 

[enderwiggin]

All I know is, I own Gerber knives in some variant of 440a, or whatever "Surgical Stainless" has come to mean, be it 420hc or "400 series stainless."

And after a few uses cutting cardboard or whatever us lamer internet geeks do at work, maybe opening a few packages for a sink install, or to install the pullman underneath, the Gerbers are worthless. I suppose I'll have to try batoning them into a log to see their superiority to S30V.

For the time being, I've been surprisingly happy with 154cm, the replacement for ATS-34. There's no amount of metallurgy that will convince me it's inferior at edge-holding to 440a or 440hc.

 

[zenheretic]

If anyone is disappointed with his S30V I'm pretty sure there is a someone on here that will happily trade out a 400 series steel for it.

 

[FernetBranca]

Enderwiggin,

As Cliff and others have pointed out in the past, one of the problems that laymen have with evaluating low carbide stainless steels is that since these are mostly used to make inexpensive knives, their heat treatment falls a long way short of optimal and this tends to mask their true potential.

Another point that is rarely appreciated is that how well an edge wears is to a very significant extent a function of its geometry, which greatly overshadows the steel's abrasion resistance. An obtuse edge will dull much faster than a more acute one - Opinels have near perfect edge geometry and on account of this achieve remarkable cutting performance with fairly soft steels.

It is also worth remembering that most blades do not dull because of wear, rather either the edge rolls or else chips/cracks. Those steels that are sufficiently soft to roll can be quickly reinstated by steeling but chipped edges require re-honing. The high carbide stainless steels do not take well to steeling and must be re-honed once the edge degrades.

Re ATS-34: Whilst it delivers good abrasion resistance, in my experience edge stability is assured only if the bevel is kept near 40 degrees included angle. Drop it down to 25 and it will micro chip and crack the moment it encounters something harder than soft pine. Yet 1090 plain carbon will hold the same 25 degree edge even whilst hacking into hard woods as long as it is tempered back to around 58Rc with almost as good abrasion resistance. I do not consider this progress.

In any event, having seen the stainless steel revolution since the introduction of 440C, for other than kitchen knives and some other high corrosion environments, I remain unimpressed and think that the common garden variety 1090 will outperform them all if given a layer of some permanent protective coating.

Regards
FernetBranca

 

[zenheretic]

I am unaware of any coating that is permanent.

 

[Nimravus Nut]

I am unaware of any coating that is permanent.

Old hard chromium coating is much more durable than today's teflon or ti-nitrate, although it's still not permanent, it still wears better. The thing is that hard chromium makes a knife look cheap.

 

[zenheretic]

Old hard chromium coating is much more durable than today's teflon or ti-nitrate, although it's still not permanent, it still wears better. The thing is that hard chromium makes a knife look cheap.

and isn't permanent...

 

[FernetBranca]

Zenheretic,

And I am unaware of any blades, especially those that chip/crak, that are permanent, though my old Gerber's hard chromium plating was as good as when I boought it some ten years down the track, and it saw plenty of use.

Nimravus Nut:

Hard Chrome does not need to look like decorative bright chrome plating. In any event, there are other acceptable alternatives that will probably work as well or better. Given today's technologies, we can even think in terms of laminates. In any event, IMHO cosmetics ought to be secondary to performance.

Regards
FernetBranca