s30v

[Jerry Hossom]

In the above photo of the two blades with differing nail cut damage, the edge that bent was a low carbon steel at Rc60. The other was 154CM at Rc61. Strength is a separate issue in steel. It is not measured by hardness. My problem from the beginning of this thread in using a low carbon steel in large blades is due to edge strength, i.e. plastic deformation as in bending and rolling. That's in addition to the fact that hard wood can wear an edge out in a hurry, and not everyone lives in a pine forest, so carbide content also matters. If this weren't true, steels like S7 and CPM-1V would be the top knife steels in the business. From my testing, CPM-3V sits right at the edge of strength versus toughness. The only failures I've seen with 3V were plastic failures induced by VERY hard impacts. Cliff reported brittle failure; I've not seen that.

Possum, you took quite a stretch to equate what I said with your correlation of carbide size, steel hardness, and strength.

Believe what you want.

I think this thread has worn me out. If someone wants to talk about large chopping blades, I'd love to do so but not in this tent.

 

[davmgt]

Good idea Jerry! It is time to put this thing to sleep! I've never seen this much egregious misinterpretation of experiment results. One positive has come from this - Ive added a new person to my ignore list!

 

[Michael Lovett]

Hey jerry! Yea I think I'm going to bow out as well. In passing, I would like to say that many confuse strength with toughness. it is two different properties. some time it pays to look at the two extremes of an issue. To see how carbon content can make the grain size smaller, rather than larger, simply break a bar of low carbon steel. especially cold rolled steel. It will have huge grain size. Now bend until yo break a high carbon bar. but before heat treat. Now heat treat the bar. You will see even with the naked eye that the grain size is many times smaller in the heat treated bar.


High carbon in industrially recognized as 1. carbon or higher. This is not what a lot of knife makers would have you think. Especially in the forging world,. But 1. Percent is the minimum to considered a true high carbon in the steel industry.


Now. I have Knives to make. Not just fantasize about.

 

[Nimravus Nut]

This is not only not true but unfounded to note that only Buck has competent heat treaters. Has ANYONE ever actually produced any FACTS that Paul Bos is a superior heat treater to the others used in the industry.


-Cliff

then why is buck the only company that people refer to when they want a reliable blade in 420 steel?

 

[Nimravus Nut]

I have precisely one experience with Mr. Bos, and it will not be my last.

I called Paul after another professional, industrial heat-treat company that "specializes" in precision HT (retaining flatness, etc) and is not unfamiliar with knives, managed to turn more than 300 Damasteel blades into potato chips. They were unable to maintain flatness despite numerous attempts. In addition, they claimed the warped blades were 59 Rc, but we tested them out at 56-57 Rc. They were aware I had to send them to Bos to fix the problems, but they still felt inclined to charge me for their efforts.

Paul straightened and hardened them to 61 Rc. (He does 100% hardness testing) and didn't charge me for the extra annealing required to straighten out the other guys' efforts.

:thumbup: :thumbup: Paul Bos is highly capable, knows knives and is a class act to top it off!:thumbup: :thumbup:

Here is where my facts are based on.

 

[Nimravus Nut]

Nimravus Nut, I think you are using forum hearsay as facts. You are indeed wrong about 154CM/ATS-34. I believe your assessment of S30V is incorrect based on my and others' experiences with the steel. I've used and continue to use it in blades over 12" and almost nothing I make is used for "small cutting". JCaswell continues to point to some pretty compelling evidence that S30V is tough, but he's ignored in favor of he said/she said kind of arguments. You can certainly search for and find matches of S30V and chipping. You've added to that search with your own posts without having a fact to support your use of those terms.

Jerry, my search on the years which 154cm/ats-34 are produced and used were indeed wrong. But back to the subject on S30v, you haven't answered the question on the usage of expensive S30v vs the usage of less expensive alternative stainless for large chopper purposes.

If a collector wants to "use or collect" your knives in S30v, it's his choice. But as users who doesn't have deep pockets, there are more viable alternatives that is just as tough and more importantly, affordable. Personally, I'll pick INFI or VG-10, even 440c over S30v anyday.

And, as I have said before, each person has his own opinions and I base my next purchase on the accumulation of opinons. When there is enough people posting that they don't like the performance of S30v, that's telling me to spend my money somewhere else.

 

[Kohai999]

If a collector wants to "use or collect" your knives in S30v, it's his choice. But as users who doesn't have deep pockets, there are more viable alternatives that is just as tough and more importantly, affordable. Personally, I'll pick INFI........

You do realize that currently available choppers in INFI run about $400.00+, right? Not to mention that they are frequently as rare as decent customs.

Try the new Spyderco Forester if you want an affordable chopper, Italian made, Hossom designed, and not a bad knife, frankly.

I recently put it through some moderate work on a sea kayaking/camping trip.

Best Regards,

STeven Garsson

 

[Nimravus Nut]

You do realize that currently available choppers in INFI run about $400.00+, right? Not to mention that they are frequently as rare as decent customs.

Best Regards,

STeven Garsson

Yep, I know the price of Infi, but my point is: dollar for dollar which one would you pick as a chopper? There is also a series of choppers designed by Hossom manufactured by Spyderco in N690 that is around $200, and Fallkniven A2 and Mineclearing knife also around $200, those are all viable stainless alternatives for choppers if you don't want to pay a $400+ price tag.

 

[Nimravus Nut]

Try the new Spyderco Forester if you want an affordable chopper, Italian made, Hossom designed, and not a bad knife, frankly.

Best Regards,

STeven Garsson

Sorry, I forgot that you mentioned it.

But it's also my point exactly. You don't have to pay $400+ for a S30v when there are other "value packed" stainless available.

I have nothing against Jerry, and I'm going to buy a Spyderco Forester to support his effort on bringing a solid, affordable design to the market.

 

[hardheart]

here's a thread where Ed Schempp talks about using 52100 in a large chopper/competition knife. He mentions the finer grain sixze, toughness, ease of sharpening, and reduced likelihood of chipping in comparison to CPM steels.

http://spyderco.com/forums/showthread.php?t=18835

a post on steels in competition cutters

http://spyderco.com/forums/showpost.php?p=304782&postcount=13

and in case anyone didn't know, Spyderco is producing knives designed by Jerry Hossom in N690 (I guess made by Fox?), & a 7" H1 camp knife & competition cutter (austempered 52100?) designed by Ed Schempp.

 

[Cliff Stamp]

Has anyone produced facts about Paul Bos?

Of course try to make it personal Jerry, what I said clearly has it been PROVEN that he is actually so much better than the competiton. Does Buck knives have a higher QC than Spyderco? Does Paul Bos have a higher QC than R. J. Martin. How about presenting some FACTS?

If you want perfect edge stability where no carbides will be dislodged under any circumstances, simply reduce the carbon to virtually zero. Carbides are what gives the steel wear resistance and strength - fundamental requirements of a knife edge. Those are the attributes which are lacking in 440A and 440hc.

Wear resistance is highly correlated to hardness (though yes carbides as well) and carbides do not give a steel strength. This shows a COMPLETE lack of understanding of even basic metallurgy. Here is an example which shows what you just stated is UTTER NONSENSE. Take an ANNEALED blade of S90V, this is chock full of carbides. Now perform any number of MEASURED MATERIALS TESTS on strength. How will it perform? Does anyone really dispute it will be very weak? Now try the nail cutting, how come it will fail badly?

Virtually all high alloy steels were developed for things other than knives. Why did industry feel the need for high carbon, high alloy steels?

In controlled cutting where impacts are low then such steels are frequently used, when impacts are frequent they are not. This is why F2 and A8 class steels both exist for cutting tools. It is also why steels like F2 will be used even though steels like D2 have much greater wear resistance. They simply can not hold fine cutting edges the same, the edge stability is too low.

Note as well you are still ignoring FACTS, steels like 52100 when heat treated properly do not actually put all that carbon into solution because it will generate plate martensite which is so brittle it is prone to cracking even when forming. 52100 has the SAME carbon in solution as the steel 12C27M you denegrated. If you are comparing the alloys then you have to look at how they actual are involved in the crystal transforms, not simply on the raw numbers. Thus if the low carbon value of 12C27M makes it inferior then 52100 is also inferior for the same reason.

Actual FACTS from Howard Clark :

[refer to 52100]

"If too much of the available 1%C is dissolved into the austenite solution, you will get "plate" martensite, which is more brittle, always, irrespective of actual tempered hardness as measured on the rockwell scale. Austenitizing temperature for 52100 should normally be held to 1550F or less. At 1550F, there will be .55-.6% of the available carbon dissolved into the austenite, with the remainder present as retained carbides in the martensite that is formed in the quench. This is good. Over-heat the blade to 1650-1700F (real easy to do by the "eyeball" method, and you may put as much as .65-.8% of the carbon into solution. This is bad."

Note his point about plate/lathe is UNIVERSAL, it is not simply an issue with 52100.

Carbide fraction & volume tells you more about strength than a Rockwell test?

As you proposed, no. The hardness test is highly correlated to tensile strength, the example of annealed steel shows the complete fallacy of the carbides = strength arguement. Spheroid annealing produces large carbide aggregates and the purpose is to make the steel DUCTILE, it is very weak as with all annealed steels. Note when you draw the temper of a steel by overheating it, you are actually coarsening the carbides and removing the alloy from the matrix itself. Now does this make the steel stronger or softer? As a known example, Talonite has a high carbide volume, but the hardness is so low the edge will deform very readily.

then why is buck the only company that people refer to when they want a reliable blade in 420 steel?

Has anyone performed blind tests to show that Buck's 420HC is actually superior to other similar priced class steels? How are Spyderco's low carbide steels such as used in the Byrd line or the AUS-6 line compared to Buck's 420HC?

here's a thread where Ed Schempp talks about using 52100 in a large chopper/competition knife. He mentions the finer grain sixze, toughness, ease of sharpening, and reduced likelihood of chipping in comparison to CPM steels.

One would hope so, otherwise a lot of ASM books on metallurgy have to be recalled. However on an amusing note there is a P/M version of 12C27/M.

-Cliff

 

[FernetBranca]

Jerry,

This is my Parthian shot ( I presume you know what that means, if not look it up somewhere)

" If you want perfect edge stability where no carbides will be dislodged under any circumstances, simply reduce the carbon to virtually zero. Carbides are what gives the steel wear resistance and strength - fundamental requirements of a knife edge."

And

"Strength is a separate issue in steel. It is not measured by hardness." .

With those statement you have demonstrated to me, and the whole world that what you know of metallurgy can be written on the back of a stamp.

Next time you decide to attack someone personally, instead of debating the issues, especially after he showed you deference, remember where this got you.


FernetBranca

 

[JCaswell]

... has it been PROVEN that he is actually so much better than the competiton. Does Buck knives have a higher QC than Spyderco? Does Paul Bos have a higher QC than R. J. Martin. How about presenting some FACTS?

I'm not sure about this PROVING he's better stuff, but here are some facts I think are relevant:

By virtue of his checking the condition of materials before treating and 100% testing after, his Quality Control is well above industry norm that I've encountered (which is often not checking at all before and checking 1 in 20 or so after unless the parts are going into aircraft or space and they're required to be more thorough).

Bos is experienced in the design and performance of HT processes sometimes specifically tailored for knife-specific applications. Jobs that would be turned down or badly muffed by most commercial heat treaters (such as HTing a stainless blade with it's edge bevels already ground without it waving or twisting out of shape). Or, as he did for me, rescuing more than $8000K in Damasteel a big-time outfit couldn't handle even though it was just flat blanks at the time.

Bos enjoys a stellar reputation as a result of decades of reliably performing HT services for a variety of challenging applications--especially knives. You might wish to imply his reputation is largely hype, but I think that would betray a lack of experience with the joys and sorrows of actually dealing with commercial heat treaters--especially for something like knives in challenging materials. It is refreshing to go to Bos and he knows what you want and how to get it and everything goes smoothly...:thumbup:

Is he the best? For the knifemaker, he's one of them at least.

 

[shaldag]

With those statement you have demonstrated to me, and the whole world that what you know of metallurgy can be written on the back of a stamp.

This is the type of insult that we don't really need to see here.
Aside from being nonsense, it is calculated to insult and for maximal rudeness.

Post reported to moderators.

 

[3Guardsmen]

This is the type of insult that we don't really need to see here.
Aside from being nonsense, it is calculated to insult and for maximal rudeness.

Post reported to moderators.

I don't think it was "calculated" at all, as "calculation" denotes thought and evaluation, neither of which were present in his comments. It was just plain insulting!

Regards,
3G

 

[Cliff Stamp]

By virtue of his checking the condition of materials before treating and 100% testing after

Check out the results of Jim March having Paul Bos heat treat the Outsider.

Bos is experienced in the design and performance of HT processes sometimes specifically tailored for knife-specific applications.

This is also not uniformly endorsed. Mayer for example strongly contests Bos heat treatment of ATS-34 which is designed for turbines, not knives (the way he hardens it). The work of Mayer is also supported directly by MEASUREMENT of performance from Landes which notes that Bos high temper scheme degrades edge stability and corrosion resistance. These are UNDISPUTED MATERIALS FACTS.

Again I ask for FACTS which prove that Bos has higher quality production wise for Buck than Spyderco or vs the other custom makers. This is supposed to be about FACTS not hype and speculation. Popularity does NOT imply let alone prove quality. I am of course not saying he is not competent. But it is a long way between that and establishing a measure of superiority which was claimed with no SUPPORT.

This is the type of insult that we don't really need to see here.

True, however said individual was insulted multiple times by multiple individuals. It is of no surprise that eventually he responded in kind. He responded multiple times calmly, even in good humor, to lack of respect.

-Cliff

 

[Bastid]

to lack of respect...

Time to let this die.

If it needs to continue, please start a thread in the testing forum.