Anyone else?

D

DavidHoback

If you see me posting, remind me to STFU & leave.
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I came across someone on the tube, who claims he is getting his steels to insane Rockwell numbers. He claims his CPM3V knives are 65.5HRC!!! He tested several 1095 blades at 67HRC. D2 blades at 66HRC. Now this alone makes for a fairly Tall Tail, but he then uses many of these knives to perform fairly rigorous tasks. For instance, the 3v at 65.5HRC belonged to an approximately 10" long blade chopper. And he uses it to cut through some raw ribs, bone and all. During that testing, he also had another of the same style of knives in CPM10V. This one was claimed to be at 67HRC!!!

I'm just wondering has anyone else heard of this nonsense? My guess is he is measuring incorrectly, which is adding several points to each test he does. But what I can't figure out is if he just doesn't understand that what he is claiming just isn't really theoretically possible, or if he is in fact thinks he can "fool" people into thinking he has made some magical heat treatment for ALL steels.

Anyway, thought I would just check here real quick. Anyone ever seen or heard this?
 
Maybe that's the hardness before tempering? I don't know how that could be possible to beat on knives that hard without major edge damage.
 
I think it might be possible to get them that hard but as it is so much harder than the steels are supposed to go I imagine there would be issues.

Don't quote me though, I am ignorant in steel hardenability.
 
I'm no big knife steel source of knowledge.
I once said that I had NEVER met a knife or edge tool that was "too hard" so . . . I used to say the harder the better.
Then some one took me by the hand and took me off the playing field and slowly explained the concept of micro chipping to me.
OK there's THAT !
And I also knew that an edge tool that is too hard and not annealed at least an itsy bit can fail catastrophically usually injuring the person driving it.
OK there's THAT.

But yah . . . I am sure the blades CAN BE that hard to start. REAL hardness testers are often quite large and expensive and like a small car without wheels to move around. There are portable sheet metal hardness testers (used on really thin test subjects) but these tend to not be accurate on thicker steel. We beat this horse into the ground in another web site; you could search sheet metal hardness tester discussions for that. Was in FWW.

For me personally I'm still, pretty much, "the harder the better" . . . think ZDP-189 up around 65 hardness but I'm careful and don't bang the blade through too many bones (none).
 
Here you go.
I copied this from a Japanese woodworking hand tool vender's catalog. They are reputable and know their stuff :
QUOTE:
The Matsumura Family has been producing woodworking chisels for well over 200 years. Mr. Shigezo Matsumura began his apprenticeship at the age of 15 and exhibited such skill that by the age of 25 he was able to open his own workshop. For over 60 years, first as an apprentice and now as a true Master of Blacksmiths, Mr. Matsumura has made chisels one at a time in the old tradition, preferring to use charcoal instead of gas in the forging and tempering process, because of its 'sof heat,' and only the finest white and blue steels for the cutting edges, which are laminated to wrought iron for strength. All cutting edges are tempered to Rc64 and sharpened for immediate use. Note: Mr. Matsumura operates a one-man shop and personally makes each tool, with occasional assist from his wife.
END QUOTE.

Here is a similar chisel. This one goes for around $500. One of my prize possessions. I have used it very hard in super hard purple heart wood. With great care though and a full understanding of it's capabilities AND LIMITATIONS.
Love this thing.

It pared these giant dove tails which are three inches long. That is a twelve inch ruler standing on edge on top the work bench in the third photo. Most drawer making dove tails are a half inch or so. But now I'm just showing off.
PS: no chipping or problems with careful tuning of the edge angle for the hardness of the wood I was working.

PPS: the last photo shows a test joint for a similar project. Cut and pared to fit perfectly but not glued up. This paring chisel is driven by driving it with two hands and a shoulder by body weight and muscle power but not hammered. Those chisels are not too hard. I could use one even harder and they do make them. Fun stuff. (ignore the metal thing in the last photo)







 
I'm not sure what any of what you just said has to do with what I asked wowbagger!!!

Hmm. Ok, well I wasn't looking for opinions from interweb rockstars. I was hoping others who actually understand this would chime in. But never mind. Can one of the Mods just delete this please.
 
To be honest depends on which steel. Different ones can be made harder than others.

In the OP the only onenthat really surprised me was the 1095. I didn't know it could be made that hard without suffering ill effects.

I knkw lots of steels can be taken into like the mid 60s for hardness.
 
David, read the crystal weaving foundation thread above... A ton of good info there. Luong's rockwell numbers have apparently been verified by other reputable knife makers, so what I think he's doing is legit and the testing is spot on. Not sure what to add other than that, sorry!
 
David,

Sorry for being vague. I'm one of Luong's fans, so my view can be said biased.

As Josh (and if you do search his threads, others too) mentioned, his claim has been validated by others (not me, my use is too light to proof BCMW CWF).

I really seriously recommend reading his thread, watching the Badhesia professor he linked (I didn't cause I know it's beyond my capacity at the moment to understand).
Then if you're interested, you can buy his knife (he provides moeny back guarantee, just check his sales thread) to try.

I'm actually looking forward for other maker to try his recipe (which he shared on that thread), so as a community we all learn more. Also hoping someone smarter to explain what and how actually he achieved what he did.

My apologies for kidding (with Wowbagger, I enjoyed lots of his hilarious comments) and not giving you a straight answer.
 
With my ht 2.x: 1095/1084/w2 max hrc is around 68. Stable/support for slicing tasks around 66rc and chopping around 64rc.

I chose 1095 to test because it is super tricky/difficult to produce clean+ultra-fine-grain+lath matrix. Similarly D2 was often used to amplifying (for delineation of changes on) attributes (e.g. brittleness). My two back-to-back 1095 videos showed edges can be varying in capability.

1095 has been around for decades and has accumulated vast empirical data (a bell curve - per se on soft/sweet/brittle ranges). Rightfully with standard ht out there so far, 58-60rc is the current optimal/sweet chopping hardness.

In my recent videos - prior testing hard tasks such as: chopping 16d nail, thick aluminum tubing, dried cooked bones. I've repeatedly state: take a blade in any steels and at any hardness with geometry 15-18dps; sub 0.020" behind edge thick, against these edge damaging tasks. Best blade at impact toughness is the one with lowest amount of damages. Pretending blade in video isn't 1095 and at unknown hrc ... not easy to find another blade out there (with similar edge geometry) can match this blade performance.


Lapedog said:
To be honest depends on which steel. Different ones can be made harder than others.

In the OP the only onenthat really surprised me was the 1095. I didn't know it could be made that hard without suffering ill effects.

I knkw lots of steels can be taken into like the mid 60s for hardness.
Click to expand...


Thanks Josh.
HRC# is very easy to verify, esp since many of my rc-tested blades are in people hand. Except for a couple blades with gradient ht (ht 1.5) - need to dig a divot toward core to reach max/tested hrc.
razor-edge-knives said:
David, read the crystal weaving foundation thread above... A ton of good info there. Luong's rockwell numbers have apparently been verified by other reputable knife makers, so what I think he's doing is legit and the testing is spot on. Not sure what to add other than that, sorry!
Click to expand...
 
I have seen the same claims and have read the associated thread. I have neither owned nor tested any of the discussed knives. That said, I see no reason to disbelieve the gentleman's data--it appears to have been verified by others in the field.

Personally, I have used CPM 3V in the 61-ish range and it was flawless and as tough as the industry standard 58-60. In many ways it was much better.

I understand 61 to 65 and higher is a huge jump in hardness. If Luong has managed to preserve toughness and stability at those levels, then hats off to him.
 
Well in the really-real world where I live, I trust the metallurgists who invented these steels, and the professional heat treaters who know what they are doing. I'd love for Paul at Boss, or Peters to chime in about this.

Thanks Chris,
But I don't need to to buy his knives, I make my own. Anyone who wishes to play make believe, go for it. There is a reason NONE of the professionals are using this "magical" heat treat recipe. I'm wondering if the test machine giving these numbers, is using a lighter load than C scale. If the load is lighter than 150kg, the number would show higher. Because the knives exhibit signs of much lower than advertised heat treat. A CPM3V blade with the toughness of a 58hrc heat treat, but actually having a 66.5hrc hardness would stay sharp forever! It could withstand extreme loads, but the edge would never fold. You can't have it both ways. Professionals know this. Which is why they pay this awno mind. But like I said, have fun in never-never land. I'll keep making knives in the real world. I have my 3v knives heat treated to 60hrc by Peters and Paul Boss. And they behave like 3v knives heat treated to 60hrc, BY PETERS & PAUL BOSS!

Bluntcut,
On a side note, many of your knives look great! You are very skilled. Good luck. :thumbsup::)
 
It's fine to wonder whether my hardness tester is not accurate (including HRC calibration block is off).
Per 3v 65.5rc #. I claimed 3V 65+rc. Here Nathan Carother confirmed my hrc #
http://www.bladeforums.com/threads/...aving-foundation.1409721/page-7#post-16269735

So, is Nathan's hardness tester also wrong? ;) Please read his performance(cut,chop,whittle nail,...) test result of that very 3V chopper. Sure just like my tests, his also could be off as well.... Nah, I don't think so :D

edit: btw - PetersHT's current Delta3V ht came from Nathan+Dan(iirc).


DavidHoback said:
Well in the really-real world where I live, I trust the metallurgists who invented these steels, and the professional heat treaters who know what they are doing. I'd love for Paul at Boss, or Peters to chime in about this.

Thanks Chris,
But I don't need to to buy his knives, I make my own. Anyone who wishes to play make believe, go for it. There is a reason NONE of the professionals are using this "magical" heat treat recipe. I'm wondering if the test machine giving these numbers, is using a lighter load than C scale. If the load is lighter than 150kg, the number would show higher. Because the knives exhibit signs of much lower than advertised heat treat. A CPM3V blade with the toughness of a 58hrc heat treat, but actually having a 66.5hrc hardness would stay sharp forever! It could withstand extreme loads, but the edge would never fold. You can't have it both ways. Professionals know this. Which is why they pay this awno mind. But like I said, have fun in never-never land. I'll keep making knives in the real world. I have my 3v knives heat treated to 60hrc by Peters and Paul Boss. And they behave like 3v knives heat treated to 60hrc, BY PETERS & PAUL BOSS!

Bluntcut,
On a side note, many of your knives look great! You are very skilled. Good luck. :thumbsup::)
Click to expand...
 
Last edited:
David,

Sorry, I forgot that you are knife maker too. Luong's HT seems to defy conventional logic, however from my very limited understanding, he's working on the crystal structure of the steel. I was about to suggest why not trying his recipe, but it seems you don't have inclination to do so, and not even reading his theory in that thread.

I also now understand that his claims are so baffling that even a knife maker like yourself refuses to try his recipe, resulting in low number of people trying this and advancing the research.

Well, I'll continue to wait for how this develops.
 
DavidHoback said:
I came across someone on the tube, who claims he is getting his steels to insane Rockwell numbers. He claims his CPM3V knives are 65.5HRC!!! He tested several 1095 blades at 67HRC. D2 blades at 66HRC. Now this alone makes for a fairly Tall Tail, but he then uses many of these knives to perform fairly rigorous tasks. For instance, the 3v at 65.5HRC belonged to an approximately 10" long blade chopper. And he uses it to cut through some raw ribs, bone and all. During that testing, he also had another of the same style of knives in CPM10V. This one was claimed to be at 67HRC!!!

I'm just wondering has anyone else heard of this nonsense? My guess is he is measuring incorrectly, which is adding several points to each test he does. But what I can't figure out is if he just doesn't understand that what he is claiming just isn't really theoretically possible, or if he is in fact thinks he can "fool" people into thinking he has made some magical heat treatment for ALL steels.

Anyway, thought I would just check here real quick. Anyone ever seen or heard this?
Click to expand...
Hi,
The internet ( like page 14) says those numbers hes reporting aren't insane
A recipe for 1095 at ~67HRC
-minimal soak (no alloy carbide)
-oil quench with no interruption from the soak
-no snap temper
-extend the quench as cold as possible
-temper twice as 325 to 350 F


What they call his type of procedure is Martempering
Another thread on it Heat Treatment - Crystal Weaving Foundation
 
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