Hardest steel available today?? (highest HRC)

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Let talk about hardness which can be measured by hardness machine. FFD2 is not 68 HRC - I see edge micro bends after cuts manila rope. This number is not result of measurement but approximation - machine need parallel surfaces to do measurement, same about H1 - someone even say it harden itself when used, which never get proved... After all Vanadium Carbide in CPM S30V is much harder but it is not blade or even edge hardness.

Currently only ZDP 189 has working hardness 67HRC but best for knives at 65HRC (very tough at this hardness).

Thanks, Vassili.
 
GregS said:
You're mistaken.
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As is Crucible?

How plausible is it they over-report the hardness on a steel they don't manufacture?


Tazkristi said:
H1 is a precipitation-hardened alloy. And yes, it is also work-hardened. Meaning that anything that you do that causes heat through friction will harden the steel further; it’s also important to note that tests have shown that it does not become brittle. The work-hardened properties of H1 have been proven by analysis independently performed by Crucible Specialty Metals. It is this that explains why an H1 blade with a SpyderEdge has better edge retention than it's PlainEdge counterpart. In the end, the analysis from Crucible found the Rc at the spine was 58, however at the edge it had increased in both the PlainEdge (to 65 Rc) and the SpyderEdge (to 68 Rc).
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nozh2002 said:
Can you provide link to thread where Tazkristi reported this results for H1?

Thanks, Vassili.
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http://www.bladeforums.com/forums/showpost.php?p=3498096&postcount=3



EDIT: Interesting post from Mr. Schempp on the Spyderco forums.


Ed Schempp said:
H-1 is an austenitic, precipitation work hardened steel. It is a totally different animal than found in cutlery. Generally martinsitic steel is used in knives. Ferro Nitride is the "hard" component in the steel and is technically a ceramic. The Nitrogen bonds to the Iron not only intra-crystal but extra-crystal as well. Bonds can actually shift iron atoms and create a stronger structure. That is why it work hardens with use...Take Care...Ed
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This is thread I started while ago to make it clear

http://www.bladeforums.com/forums/showthread.php?t=478438

To me it seems that it was some microhardness testing and may not really equal to real blade with 65HRC. Again some microscopic parts may be this or even more hard, but this little particle may not really improve performance.

This is what make me finally lost any interest in this "work hardening" thing:

Sal Glesser said:
Hi Vassili,

I personally cannot say that a non mechanical use will make the blade harder. We have no evidence to support that. We have had a few customers say thet they believe it to be true, based on their personal expericences.

As far as what ae can and cannot do, we're still learning about this interesting new material.

sal
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Thanks, Vassili.
 
basing an opinion on that quote from sal would be excluding 3 years of information, testing, and use.
 
nozh2002 said:
This is thread I started while ago to make it clear

http://www.bladeforums.com/forums/showthread.php?t=478438

To me it seems that it was some microhardness testing and may not really equal to real blade with 65HRC. Again some microscopic parts may be this or even more hard, but this little particle may not really improve performance.

This is what make me finally lost any interest in this "work hardening" thing:



Thanks, Vassili.
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Vassili, did you not notice this post on your very own thread?

Sal Glesser said:
Hi Vassili,

Crucible did do micro hardness testing on the Salts and determined that the blades were in fact work hardened in the grinding processes and was 65 at the edge of the plain edge model and harder at the edge of the serrated edge model.

sal
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Sal specifically stated grinding work hardened the blades.

Why is your opinion different from this now?

Keep in mind, you asked about the blade work hardening from leather, NOT from mechanical grinding as would be the case in serrating the knife.

nozh2002 said:
Thanks Sal,

This is not a hype! Cool. Are there any numbers any practical recommendations? I use a lot of friction while sharpening and polishing the blade on leather I am wondering will it be enough... Is it heat from friction or mechanical pressure? Why don't you put attitional friction on edge as part of manufacturing process?

Thanks, Vassili.
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MORIMOTOM said:
basing an opinion on that quote from sal would be excluding 3 years of information, testing, and use.
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It doesn't matter because he's just playing games here..
 
huugh said:
Besides that, ultrahard fullerite and especially aggregated diamond nanorods are thought to be the hardest substances.
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..........oh yeah, now I see the high bit.....:D In that case I second the question...

zyhano said:
but not a metal. and actually, diamond is not the hardest known substance (check out nanotubes: http://en.wikipedia.org/wiki/Carbon_nanotube#Hardness)
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Well then gentlemen on my second statement, I stand corrected. Good to know. Update the knowledge rolodex.
 
I think one would have to contact a Company Rep to request/confirm Testing Certs or promoted Rc on any given blade, or have an Rc test done on their own knife.

I wonder about steels like Cowry X or CPMS125V core clad with S30V - which are used in Japanese cutlery?

Here is an older BF thread that discusses the Cowry X & Y and ZDP steels - http://www.bladeforums.com/forums/showthread.php?t=242567
 
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it might be a dead horse but i need to hear clarifs. when you say zdp 189 or cpm m4 can be hardened to rc 67 or 68, i take that to mean quench hardness. when quenched, the steel is usually so brittle you can snap it in your hand, or smash it by hurling it to the floor. rc 63-64 for a knife edge sounds more plausible, following some kind of tempering after quench hardening. am i correct?

i know for a fact that most furnace tool steels can be hardened to rockwell 64 but have to be gross tempered down to 62 (the hardness of a file.) for knife blades, it's further tempered to 58-59.
 
it might be a dead horse but i need to hear clarifs. when you say zdp 189 or cpm m4 can be hardened to rc 67 or 68, i take that to mean quench hardness. when quenched, the steel is usually so brittle you can snap it in your hand, or smash it by hurling it to the floor. rc 63-64 for a knife edge sounds more plausible, following some kind of tempering after quench hardening. am i correc
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No, they are talking about after quench. In addition CPM M4 can easily run at rc 65, M2 at 66, Cruwear at 63-64, S110V at rc 63.5-64, 10V at 64, D2 at 63 etc., etc..

Joe
 
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Besides....it's REX 121 at 72 rockwell

http://www.britishblades.com/forums/showthread.php?111971-Farid-CPM-REX-121-knife
 
Wow, back from the dead.... anyway, lots of tool steels can have a working hardness in the 70's Rc. Pertaining to the hardest "metal", tungsten carbide takes the cake. Hardness ranges from the mid 90's to over 100 Rc. Very brittle though, and not worth a crap as a knife blade.

Regarding M42 cobalt, it may get a little harder than M4 or M2, but the main benefit is that it has a very high red hardness when used in a milling cutter. Again, not worth a crap as a knife blade.
 
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