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Steel Hardness In Production Knives

Posted by jasonstone20 
Re: Steel Hardness In Production Knives
October 29, 2019 08:01PM
[www.youtube.com]




Well this is disappointing. CATRA didn't sharpen the blades all the way to the ricasso and there were visible burrs on all the blades.

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"Gotta love living in 2019 baby, (63rc too soft on a production knife)"
--Shawn Houston
__
"I am still discussing issues of steels and performance at this stage."
--Cliff Stamp
__
"Cause geometry cuts, .....steel determines the level and the duration"
--Roman Landes
__
"But in general, I'm all about high performance, Ergos, safety. That's why I've been accused of 'designing in the dark' "
--Sal Glesser
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StoneSharpEdges

Jason D. Stone on YouTube
Re: Steel Hardness In Production Knives
November 07, 2019 08:25PM
The fact that there were visible burrs on all the knives should be a problem for CATRA testing in general. Those edges would collapse readily if used by hand. They fact that most test knives are destroyed after testing is another issue AND that they can't sharpen a knife should raise red flags. No wonder Sypderco does their CATRA testing in house. Also they can't account for any lateral loads makes the tests almost useless for knives that are cut by hand.

------------------------------------------------------------------------------------------------------------------------------------------------------
"Gotta love living in 2019 baby, (63rc too soft on a production knife)"
--Shawn Houston
__
"I am still discussing issues of steels and performance at this stage."
--Cliff Stamp
__
"Cause geometry cuts, .....steel determines the level and the duration"
--Roman Landes
__
"But in general, I'm all about high performance, Ergos, safety. That's why I've been accused of 'designing in the dark' "
--Sal Glesser
------------------------------------------------------------------------------------------------------------------------------------------------------
StoneSharpEdges

Jason D. Stone on YouTube
Re: Steel Hardness In Production Knives
November 08, 2019 06:14AM
Quote
jasonstone20
The fact that there were visible burrs on all the knives should be a problem for CATRA testing in general. Those edges would collapse readily if used by hand. They fact that most test knives are destroyed after testing is another issue AND that they can't sharpen a knife should raise red flags. No wonder Sypderco does their CATRA testing in house. Also they can't account for any lateral loads makes the tests almost useless for knives that are cut by hand.
I don't think that "can't account for any lateral loads" makes the test useless. Human testing has random lateral loads and the CATRA test has a constant lateral load. Regardless, CATRA correlates strongly with rope slicing.
Re: Steel Hardness In Production Knives
November 08, 2019 07:22AM
Larrin,
Yes, and that was going to be my next question, since the CATRA lines up with slicing rope tests and cardboard cutting. Why bother to use Sal Glessers method of sharpening, Cliff's 3-Step or Plateau sharpening, or bother to de-burr at all if the CATRA tests with visible burrs still lines up with rope and cardboard cutting? Also, to clarify what I meant by almost useless is that if the edges have visible burrs (most burrs are not visible, they have to be extremely large to what is usually used in most hand sharpening, when they have to be felt by hand), that I am assuming burred edges are more sensitive to lateral loads (since CATRA there is at least one flaw in CATRA's test, the random lateral loads), it appears that there are now edge angle accuracy problems along with not being able to sharpen the whole edge. I wasn't trying to say CATRA was useless, I maybe was a hyperbolic in my phrasing, but CATRA was being held up as the ultimate standard by the naysayers in the groups experiments instead of a useful data point, which I don't think there is any don't that it is.

------------------------------------------------------------------------------------------------------------------------------------------------------
"Gotta love living in 2019 baby, (63rc too soft on a production knife)"
--Shawn Houston
__
"I am still discussing issues of steels and performance at this stage."
--Cliff Stamp
__
"Cause geometry cuts, .....steel determines the level and the duration"
--Roman Landes
__
"But in general, I'm all about high performance, Ergos, safety. That's why I've been accused of 'designing in the dark' "
--Sal Glesser
------------------------------------------------------------------------------------------------------------------------------------------------------
StoneSharpEdges

Jason D. Stone on YouTube
Re: Steel Hardness In Production Knives
November 08, 2019 09:38AM
I think there is somewhat of an overreaction to a few who complained about less "controlled" testing. Now there is excitement about declaring victory and therefore have to put down the catra test to do it.
Re: Steel Hardness In Production Knives
November 08, 2019 07:24PM
Larrin,
That is a very level headed way to look at the situation. I don't like the drama involved in the whole situation. That being said, as much as CATRA testing is respected, the methods used were poor in my opinion, which to be honest was disappointing. There was somewhat of a shock factor to the results.

------------------------------------------------------------------------------------------------------------------------------------------------------
"Gotta love living in 2019 baby, (63rc too soft on a production knife)"
--Shawn Houston
__
"I am still discussing issues of steels and performance at this stage."
--Cliff Stamp
__
"Cause geometry cuts, .....steel determines the level and the duration"
--Roman Landes
__
"But in general, I'm all about high performance, Ergos, safety. That's why I've been accused of 'designing in the dark' "
--Sal Glesser
------------------------------------------------------------------------------------------------------------------------------------------------------
StoneSharpEdges

Jason D. Stone on YouTube
Re: Steel Hardness In Production Knives
November 09, 2019 05:39PM
But even with the edges looking bad after getting the knives back the curves generated by CATRA look good. So it is hard for me to say how bad or good it even was. Perhaps the testing was better than it is being characterized.



Edited 1 time(s). Last edit at 11/09/2019 05:39PM by Larrin.
Re: Steel Hardness In Production Knives
November 10, 2019 08:06AM
I think you would expect to see some edge damage (they should be coming back dull, after all), but a lot of what we see there I think is outside of what would normally happen and more a result of a one size fits all sharpening - which makes sense they use, to produce a fair comparison - but that kind of threw the baby out with the bathwater as far as caring about the knife as a tool. Probably why they destroy the blades after, so people won't complain about their methodology after getting a bit of a shock seeing how the knives end up.
Re: Steel Hardness In Production Knives
November 10, 2019 08:16AM
My dream is to one day have a CATRA tester. If only...
sal
Re: Steel Hardness In Production Knives
November 11, 2019 12:33PM
I don't think that CATRA is the "ultimate" tester. It's was just the most consistent lab test that we could find. Our original cutting machine cut insulation, but the tests took too long with thousands of cuts. I still like "Real-World-Testing", and I also like to see other tests done by knife afi's.

We usually test "Mules" which are consistent in dimensions and sharpened by a robot for consistent edges. No burrs. We have currently redesigned our "Mules" and will be retesting all steels with the new test piece. We don't throw them away, we have an extensive file all tested pieces. When we test a knife instead of a "Mule", we resharpen and sell it at our 2nds sale.

sal.
Re: Steel Hardness In Production Knives
November 11, 2019 01:23PM
Quote
sal
I don't think that CATRA is the "ultimate" tester. It's was just the most consistent lab test that we could find. Our original cutting machine cut insulation, but the tests took too long with thousands of cuts. I still like "Real-World-Testing", and I also like to see other tests done by knife afi's.

We usually test "Mules" which are consistent in dimensions and sharpened by a robot for consistent edges. No burrs. We have currently redesigned our "Mules" and will be retesting all steels with the new test piece. We don't throw them away, we have an extensive file all tested pieces. When we test a knife instead of a "Mule", we resharpen and sell it at our 2nds sale.

sal.
I agree that the CATRA is the most consistent test currently available. Of course, there aren't many alternatives.
Re: Steel Hardness In Production Knives
November 20, 2019 09:09PM
Some HRC testing:
[www.youtube.com]




------------------------------------------------------------------------------------------------------------------------------------------------------
"Gotta love living in 2019 baby, (63rc too soft on a production knife)"
--Shawn Houston
__
"I am still discussing issues of steels and performance at this stage."
--Cliff Stamp
__
"Cause geometry cuts, .....steel determines the level and the duration"
--Roman Landes
__
"But in general, I'm all about high performance, Ergos, safety. That's why I've been accused of 'designing in the dark' "
--Sal Glesser
------------------------------------------------------------------------------------------------------------------------------------------------------
StoneSharpEdges

Jason D. Stone on YouTube
Re: Steel Hardness In Production Knives
November 20, 2019 09:54PM
Cliff, me2, and others discussing how important HT are for steels:
[www.bladeforums.com]

------------------------------------------------------------------------------------------------------------------------------------------------------
"Gotta love living in 2019 baby, (63rc too soft on a production knife)"
--Shawn Houston
__
"I am still discussing issues of steels and performance at this stage."
--Cliff Stamp
__
"Cause geometry cuts, .....steel determines the level and the duration"
--Roman Landes
__
"But in general, I'm all about high performance, Ergos, safety. That's why I've been accused of 'designing in the dark' "
--Sal Glesser
------------------------------------------------------------------------------------------------------------------------------------------------------
StoneSharpEdges

Jason D. Stone on YouTube
Re: Steel Hardness In Production Knives
November 23, 2019 10:05PM
[www.youtube.com]




------------------------------------------------------------------------------------------------------------------------------------------------------
"Gotta love living in 2019 baby, (63rc too soft on a production knife)"
--Shawn Houston
__
"I am still discussing issues of steels and performance at this stage."
--Cliff Stamp
__
"Cause geometry cuts, .....steel determines the level and the duration"
--Roman Landes
__
"But in general, I'm all about high performance, Ergos, safety. That's why I've been accused of 'designing in the dark' "
--Sal Glesser
------------------------------------------------------------------------------------------------------------------------------------------------------
StoneSharpEdges

Jason D. Stone on YouTube
Re: Steel Hardness In Production Knives
January 07, 2020 07:19PM
Apparently Benchmade has updated their 3V in the Bailout from 55-56HRC to 60-62HRC:
[www.youtube.com]




------------------------------------------------------------------------------------------------------------------------------------------------------
"Gotta love living in 2019 baby, (63rc too soft on a production knife)"
--Shawn Houston
__
"I am still discussing issues of steels and performance at this stage."
--Cliff Stamp
__
"Cause geometry cuts, .....steel determines the level and the duration"
--Roman Landes
__
"But in general, I'm all about high performance, Ergos, safety. That's why I've been accused of 'designing in the dark' "
--Sal Glesser
------------------------------------------------------------------------------------------------------------------------------------------------------
StoneSharpEdges

Jason D. Stone on YouTube
Re: Steel Hardness In Production Knives
January 08, 2020 07:25AM
Hah, props for actually doing it I guess. Although with their new M4 version coming out I wonder what they're going to do with that.
Re: Steel Hardness In Production Knives
January 08, 2020 12:19PM
Luis,
Not sure. It just goes to show that you can get companies to correct behavior that isn't favorable to the knife purchasing community. I think that is the real reason you saw so much push-back from people about the work these guys were doing. To be honest, it looks to be a tireless, thankless job to hold knife makers and knife companies to task. Cliff usually is at the leading edge of that work, and since he's been engaged in other things, the work still needs to be done, and the knife makers and manufacturers are just as unhappy.

------------------------------------------------------------------------------------------------------------------------------------------------------
"Gotta love living in 2019 baby, (63rc too soft on a production knife)"
--Shawn Houston
__
"I am still discussing issues of steels and performance at this stage."
--Cliff Stamp
__
"Cause geometry cuts, .....steel determines the level and the duration"
--Roman Landes
__
"But in general, I'm all about high performance, Ergos, safety. That's why I've been accused of 'designing in the dark' "
--Sal Glesser
------------------------------------------------------------------------------------------------------------------------------------------------------
StoneSharpEdges

Jason D. Stone on YouTube
Re: Steel Hardness In Production Knives
January 22, 2020 10:57PM
[www.bladeforums.com]

Quote
Deadboxhero
Well the user is in full control of the edge Geometry, degrees of angle and flat vs Convex. Lower flatter angles cut more, thicker convex edges are more durable.



On paper M390 seemed to be the top dog for production knives. Yet it didn't add up always.

Some backstory.

2019 a group of testers came together to try to and understand why they were all getting low numbers for their cut testing with what should be superior steel. They noticed the edge retention was dismal to S30v etc. They then sought further testing, They were able to get the knives HRC tested and noticed low Rockwell values and caused quite an upset in the community.

After they were dismissed for being "BroScience" they find raised money to send out production knives for more Scientific testing to CATRA in the UK. Three folders in M390 and a one in S30v for control. All the m390 was from different companies and hardness from 58-62rc

Well, the CATRA showed that when the HRC was low on the M390 (58rc) it underperformed S30v (61rc) that was slightly harder.

Even though s30v has a lower total volume of carbide. M390 is mostly chromium carbide (17.5%) and less volume of the more effective Vanadium carbide (2.5%)
Compared to S30v (10.5%) chromium carbides and (4%) Vanadium Carbides

When the M390 was at the same hardness as S30V, M390 cut more.

M390 is not like S90v which can cut longer at slightly lower HRC in controlled wear cut testing since it has more of the harder Vanadium Carbides (9%) and (13%) chromium carbides.

Yet, folks love M390 and many claim it sharpens better and holds a longer edge for them real world vs S30v. Could be a mix of placebo or the fact that it just gets sharper with THEIR tools and techniques with less Vanadium carbides to cut through to shape the apex. Who knows.

So I find it silly to dismiss a steel like SPY27. For not having enough carbide volume. How everything works is more complex.

When you bottom out the hardness on the M390, all that wear resistance on paper didn't add up to edge retention one would expect yet you still get all the detriments of those carbide reducing the edge stability and tougheness. Carbides are tiny hard inclusions in the steel that can promote the edge to be more brittle since they are brittle particles themselves but also serve to act as areas crack initiation. Cracks will connect the dots through the carbides and cause blow out vs lower volume is less prone.

So high carbide steels under 59rc are the worst of both worlds.

For example, I wouldn't dare make a custom in Rex 121 at 58 rc to make tougher. At 30% carbide volume toughness is going to suck anyways and the Stability will be bottomed out for impact toughness not edge toughness, matrix is too soft to hold those Carbides so they can resist wear when the matrix that holds them is soft. My point is lower HRC doesn't make something designed for other applications edge tough/stable

I suppose manufacturers need to stop being scared and bump the hardness and deal with the warranty fall out from those that refuse to use them properly and move those folks to another steel. 3v at 56rc lmao jk but you can see the fundamental problem in the community and it's not just the steel, its the audience too.

Now some folks can't handle this level of detail and the duality between the different things I'm describing and will think I'm saying Carbides are the devil.

No.

A steel devoid of Carbides will wear smooth faster even at high 66 HRC and just doesn't have that edge aggression folks like for edge that grab and bite ferociously.

So in reality, you're damned if you do, damned if you don't.

If you want the same Edge Retention from high carbide steels you see in controlled testing in real world you need to step your game up, use proper stones and sharpening techniques and use it like a knife, not a toliet wand.

I've always been one to point out the trade offs involved with carbides and that they are a necessary evil if you want the maximum hardness and cutting retention in a controlled environment. Yet, in the real world, since people are all over the place with sharpening and use, it just doesn't always seem to translate to everyone or everything so it's nice to have options for people.

Vanax Superclean was supposed to be similar to Elmax in wear resistance on paper. Yet, in real world, it destroys Elmax for people and always tests high in social media cut testing and with users.

So, there is a lot going here and I'd like if folks could appreciate it.
Otherwise y'all need to only use s125v and Rex 121 cause In testing nothing out cuts those steels, not even Vanax unless the sharpening isn't good.

I am okay with that too. I love those steels grinning smiley

------------------------------------------------------------------------------------------------------------------------------------------------------
"Gotta love living in 2019 baby, (63rc too soft on a production knife)"
--Shawn Houston
__
"I am still discussing issues of steels and performance at this stage."
--Cliff Stamp
__
"Cause geometry cuts, .....steel determines the level and the duration"
--Roman Landes
__
"But in general, I'm all about high performance, Ergos, safety. That's why I've been accused of 'designing in the dark' "
--Sal Glesser
------------------------------------------------------------------------------------------------------------------------------------------------------
StoneSharpEdges

Jason D. Stone on YouTube
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