SE H2 beats PE Rex121 at edge retention??

[hobbyist]

Maybe this was already discussed:



Is this actually true? What’s the methodology? Does catra do serrated?

[vivi]

they used to say the same thing about SE H1 while offering S110V, K390, Maxamet etc., so this doesn't surprise me much.

[ZenL]

Yeah, this seems odd to me too, there are a lot of variables when it comes to edges and without the methodology it's hard to say if they're controlling for them all. I'm also assuming they mean SE H1/H2 surpasses PE tool steels, but surely SE H2 does not outperform SE K390, right?

[shunsui]

It always amazes me how people just don't seem to get it.

[James Y]

I seem to remember Sal saying that the SE Jumpmaster 2 in H1 tested out as having the highest edge retention of any blade, in any blade steel, that they ever tested. If I'm misremembering, then I'm sure Sal or someone else will correct me.

Is SE H2 really any different from SE H1?

Jim

[WilliamMunny]

I seem to remember Sal saying that the SE Jumpmaster in H1 tested out as having the highest edge retention of any blade, in any blade steel, that they ever tested. If I'm misremembering, then I'm sure Sal or someone else will correct me.

Is SE H2 really any different from SE H1?

Jim

No I think you are correct, I think I also heard Eric say something to that extent. H1 and H2 are the same steel. If I remember correctly they had to rename it for licensing issues, changing it ever so slightly.

[Deadboxhero]

The relationship between plain edge and serrated edge simplified from CATRA testing data.




The serrated edge did not cut as well initially but did not change much after initial dulling.

The plain edge cut more initially but changed by comparison more rapidly with dulling.

There can be circumstances in real world use that one will show more edge retention than the other.

Maybe this was already discussed:



Is this actually true? What’s the methodology? Does catra do serrated?

[hobbyist]

The relationship between plain edge and serrated edge simplified from CATRA testing data.




The serrated edge did not cut as well initially but did not change much after initial dulling.

The plain edge cut more initially but changed by comparison more rapidly with dulling.

There can be circumstances in real world use that one will show more edge retention than the other.

Maybe this was already discussed:



Is this actually true? What’s the methodology? Does catra do serrated?

Very interesting thanks for sharing, I wonder, is this generally true for all serrated? Like does VG-10 beat out Rex121 in the same way?

[Wartstein]

The relationship between plain edge and serrated edge simplified from CATRA testing data.




The serrated edge did not cut as well initially but did not change much after initial dulling.

The plain edge cut more initially but changed by comparison more rapidly with dulling.

There can be circumstances in real world use that one will show more edge retention than the other.
..

This is really interesting.

I prefer (Spydercos) SE over PE in their folders.

And in my completely unscientific experience a factory serrated edge actually almost always cuts "better" (deeper, more effortless...) out of the box than a plain edge does (so also "initially" cuts "better").

- Could it be that the Catra test compensates for the chisel grind of Spydercos SE?
- So while a serrated Spyderco normally comes in a steeper inclusive edge angle than the same knife in plain edge, in a Catra test comparison it is made sure that both PE an SE have the same angle? (And THEN PE wins)
(And on the other hand a serrated Spyderco "just" cuts "better" than PE not due the serrations themselves, but rather due to the steep chisel grind SE comes in?)

- What I can "confirm" (also completely unscientific though): Just going by how long a knife can separate matter decently, SE remains "sharp" a lot longer than PE in the same knife.

[Wartstein]

The relationship between plain edge and serrated edge simplified from CATRA testing data.



The serrated edge did not cut as well initially but did not change much after initial dulling.

The plain edge cut more initially but changed by comparison more rapidly with dulling.

There can be circumstances in real world use that one will show more edge retention than the other.

And:

These findings are related to PE in general and SE in general, right?

The to me still weird thing though is the H1/H2 situation:

Just and particularly with H1 (H2) serrated there is that work hardening thing, but not with PE in the same steels.

So Eric (and Sal, and others) in this case are not saying that SE in general beats PE in edge retention.

But that specifically H1(H2) gets some superior hardness only when serrations are grind into that steel.

I still don´t fully get that (and I seem to recall that @Larrin does not really confirm it, but don´t quote me on this!)

[Jesla]

It’s my understanding that “work” hardening requires a certain amount of deformation of the material.
Machining said materials is not deforming. Now can machining work harden the surface?… Maybe, at least in the way peening hardens the surface. However any sharpening of the tool will remove that “hardened” micro surface.

[cjk]

The relationship between plain edge and serrated edge simplified from CATRA testing data.




The serrated edge did not cut as well initially but did not change much after initial dulling.

The plain edge cut more initially but changed by comparison more rapidly with dulling.

There can be circumstances in real world use that one will show more edge retention than the other.

Maybe this was already discussed:



Is this actually true? What’s the methodology? Does catra do serrated?

My impressions from reading knifesteelnerds.com:
I believe that a CATRA blade is a rectangular thing kinda like a bigger razor blade. The cutting edge is straight.
In a CATRA machine, it looks like all of the edge of a plainedge would get used in the test.
On a serrated blade, it would appear to me that mostly the points of a serrated blade would get used in the test.
The more the SE points dull, the more of the edge in the larger scallops would be exposed and then get used, so the poorer initial performance of the SE may be easily explained. Less of the actual edge is being used.
And the better edge retention is slightly explained too as less of the edge gets used, so less of it is dulled (even though it might not cut as well as PE in that specific test). The sharpened edge of a SE knife is longer than the sharpened edge of a PE knife of the same length due to the SE's wavy edge.

What I'm attempting to describe might be easier to visualize if one puts a serrated wharncliffe on a flat surface and look at how much edge actually touches the surface. Only the points do. On a plainedge wharncliffe, the whole edge would touch the medium.

When I cut a thing with my serrated knife, I'm often using more of the edge than what I'm thinking the CATRA test does.

In practice, I think I touch up the sharpening of a serrated knife about as often as I do on a plainedge knife.

Of course, I'm no expert. I may be totally off base.

--Christian

[Evil D]

It’s my understanding that “work” hardening requires a certain amount of deformation of the material.
Machining said materials is not deforming. Now can machining work harden the surface?… Maybe, at least in the way peening hardens the surface. However any sharpening of the tool will remove that “hardened” micro surface.

This is the question I've been asking since the first time I heard about work hardening, how deep does it go? Then it was said that the act of sharpening it yourself contributed to the hardening, but then it was said that the grinding of serrations is a more aggressive action and that's what causes it. So then some guys got the idea, if grinding is work hardening then can we regrind a PE blade and get the same results? Which turned out to not really be the case and I've always suspected that if this were possible then Spyderco surely would be doing something like this to enhance H1 performance.

[zuludelta]

When I cut a thing with my serrated knife, I'm often using more of the edge than what I'm thinking the CATRA test does.

In practice, I think I touch up the sharpening of a serrated knife about as often as I do on a plainedge knife.

This might help explain the CATRA chart for SE, and it could also account for why those findings might not necessarily be reflected in real-world use.

In general, I've found that—steel type being constant—Spyderco's SE blades will either match or outlast (sometimes not by much, sometimes by a lot) their PE equivalent as far as what I consider a working edge is. As to why this is, I've always largely attributed it to the acute angle & chisel-grind of Spyderco's SE.

I used to prefer SE & CE folders for work because of this observation, but eventually switched to PE because the larger amount of gunk & loose fibers (when cutting rope/rough-finished cardboard) SE folders accumulate over the course of a shift can be a pain to clean & on more than one occasion has interfered with the knife's lock-up. I was comfortable trading whatever extra performance I was getting from SE for the slightly easier maintenance of PE.

[navin johnson]

Been talked about since H1 came out

Search for the many threads

[zhyla]

Would be nice to see H1/H2 SE up against another steel in SE. The claims are always apples and oranges.

[Wartstein]

This is the question I've been asking since the first time I heard about work hardening, how deep does it go? Then it was said that the act of sharpening it yourself contributed to the hardening, but then it was said that the grinding of serrations is a more aggressive action and that's what causes it. So then some guys got the idea, if grinding is work hardening then can we regrind a PE blade and get the same results? Which turned out to not really be the case and I've always suspected that if this were possible then Spyderco surely would be doing something like this to enhance H1 performance.

What I still don´t fully understand:

- When it comes to edge retention serrated H1/H2 and plain edge H1/H2 are said to be on pretty much the opposite ends of the spectrum: PE really nothing to write home about, SE "better than PE REX121"

- How can it be that grinding serrations leads to that pretty extreme work hardening, but grinding a plain edge not (or at least by far not as much??

- I mean it is not like it is with how ancient bronze swords were hardened: By hammering / compressing the edge, so that it actually got denser (and by that harder) the thinner it got, but not by removing material

- When grinding an edge into H1/H2, I figure the grinding process itself happens with approximately the same force both when grinding PE or SE, the latter just creates a different shape and partly goes deeper into the steel.
But grinding SE "just" removes more material (at least on ONE side of the blade, on the other one actually less), but does not create more "force" and by that "work hardening"?

[zhyla]

- How can it be that grinding serrations leads to that pretty extreme work hardening,

Is that the theory? I thought it was the usage that was theorized to work harden the edge. I must be misremembering.

but grinding a plain edge not (or at least by far not as much??

My theory is whatever is going on, if anything, it’s on the pointy tips of the serrations. The geometry is very different there vs the scallops. The scallops are just tiny PE sections.

[Wartstein]

- How can it be that grinding serrations leads to that pretty extreme work hardening,

Is that the theory? I thought it was the usage that was theorized to work harden the edge. I must be misremembering.

but grinding a plain edge not (or at least by far not as much??

My theory is whatever is going on, if anything, it’s on the pointy tips of the serrations. The geometry is very different there vs the scallops. The scallops are just tiny PE sections.

I am sure the theory is indeed that it is the GRINDING that leads to the "work hardening"... if it was just usage this would make it even more mysterious (not even sharpening leads to (further) "work hardening", as far as I recall).

/ And they say that the edge retention is enhanced with that "work hardening" of H1/H2... so, no offense meant, but your theory that only the "pointy tips" are "hardened", would not make real sense, would it? Because then the edge would not last and cut longer...?

[olywa]

I have valid use cases for both PE and SE, and I usually have one of each on me. PEs are not really a mystery to me. What I really want to see is some comprehensive testing and comparisons of SEs in H1&2/VG10/LC200N/BD1N/XHP/K390/MAGNACUT. I have examples of each, except LC200N (I need to remedy that), and they all perform well.

Some are harder to sharpen than others, but once sharp they all seem to hold their edge pretty darn well. But how well in comparison to each other would help me figure out where the juice ain't worth the squeeze in terms of up-front costs and downline maintenance efforts. Of course it would all be pretty subjective, what with differing serration patterns and edge angles.