SE H2 beats PE Rex121 at edge retention??

[zhyla]

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).

Huh. So once you sharpen enough the effect goes away?

I continue to be suspicious of this phenomenon. Would be really nice to see an apples to apples comparison.

I was just re-reading the KnifeSteelNerds article on H1. They didn’t see increased hardness at the edge, though it does not specify PE or SE. The article theorizes the work hardening would be superficial though.

[cabfrank]

Remember, "The edge is a ghost".

[JoviAl]

I’m no metallurgist (today I shall again don my alter ego of Anecdotal-Al ) but I do do a fair bit of welding to make custom chainsaw exhaust pipes. When I’m welding them I often have to give them a little kiss of persuasion with a 1KG (~2lbs in freedom units) block hammer to get the parts neatly aligned before running final beads. If I just spank the snot out of the metal it always cracks, but if I apply a bit of heat and get the steel nice and cherry red it seems to relax the structure and once cooled can handle more ‘gentle persuasion’. My friend Tom who is a doctor of engineering told me that I was work hardening the steel with the hammer and causing compression and micro fracturing of the structure, but heating it to cherry red again relaxes the bonds between molecules and allows it to go through a bit more working before failure (cracking). Working off this as a premise, if Spyderco is grinding the scallops with the grinding apparatus under pressure then it may account to some degree for this anomalous phenomenon.

I’ve often wondered if I might recreate the phenomenon by sharpening the scallops individually with my Foredom and porting equipment, as it would be fairly straightforward to introduce localised intense heat, pressure or both with my equipment. Up until today I’ve just never been bothered enough to try, as my SE H1 and H2 knives’ performance is generally outstanding. Once I’m back at work in January I might give it a try and record my results on here.

[wrdwrght]

Rightly or not, “work-hardening” (presumably, chiseling and scalloping of the edge) is what has been cited on the forum (at least since I joined) to explain sharpness persisting on SE longer—much longer—than on PE in H1 (=? H2).

I’ve not heard that sharpening hardens PE. The higher heat of machine-grinding seems (implicitly?) to be work-hardening‘s essential quality.

What I have heard (chiefly from Vivi), and confirmed in my own use, is that PE’s sharpness in H1 (=? H2) can be sustained longer when the apex is more acute than what the Sharpmaker offers. I’ve had improvement freehanding ≈15°inclusive.

[sal]

Talkin' story;

There is much discussion. Gail and I had been studying serrations in the late 70's. We saw advantages, so we developed a tool that we felt would effectively sharpen any type of serration for better performance. That tool was the 201 Sharpmaker, quickly followed by the 202. (we are now in the 204).

We (wrongly) believed that everyone would see the advantages of serrations and be able to sharpen them. We then designed the "Worker" model Clipit. It was a few years later, and no one brought out serrations, so we added them to our 2nd Clipit model, The Mariner", which later became the "Rescue". (circa 1982).

As mentioned, "The Edge is a Ghost". Not all serrations are the same. We tested H1 quite a bit before using it. The blade edge was noting to brag about, but sharpened up easily. The best part being that it didn't rust in salt water. The serrated edge performed far better than expected. One of the metallurgists at Crucible tested it and said he thought that the performance improvement was due to the work hardening of the steel when grinding,especially the serrations.

In my opinion, there is much to learn about teeth, though too few have dug down. That's why we stickied David's
post on teeth. He was persistent in learning the "care and feeding of serrations". I would like to see more testing done on our teeth, and even others, there is much to be learned.

sal
--------------------------------------------------------------------------------------------------------------------------

"Continual improvement is our evolutionary obligation to Humankind".

[Wartstein]

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).

Huh. So once you sharpen enough the effect goes away?
...

I really have no idea.. I was just parroting what I gathered so far from reading stuff, and that is - I think - that actually and only grinding an edge into H1 leads to that "work hardening" (and for whatever reason much more so with SE than with PE)

And if just the light touch of sharpening would lead to (further) work hardening, this would it make even more confusing that this should happen with SE much more so than with PE- I mean, the end user is applying about the same (very light) pressure on both edge tpyes - personally, if at all, I tend to use even lighter "pressure" on SE than PE when sharpening a knife.

But of course your point raises the question (that has been asked before of course):
How deep / how far up the blade does the "work hardening" go?
So COULD one actually sharpen the "work hardened area" away over time?

[Wartstein]

... One of the metallurgists at Crucible tested it and said he thought that the performance improvement was due to the work hardening of the steel when grinding,especially the serrations.
....

But Sal, what IS the actual difference between grinding a plain edge and grinding a serrated edge into a H1/H2 blade in your opinion?

I mean there must be a difference, if it is the actual grinding process itself that does lead to such superior edge retention in serrated H1, but really not so in plain edge H1...

More time, pressure, force, heat?? when grinding serrations into H1?

And IF one of those things (time, pressure..) leads to much better edge retention in serrated H1 - why not just apply more time, pressure, heat, force, whatever the factor might be also when grinding plain edge H1 so that PE would hold an edge longer too in that steel?

[Wartstein]

...My friend Tom who is a doctor of engineering told me that I was work hardening the steel with the hammer and causing compression and micro fracturing of the structure, but heating it to cherry red again relaxes the bonds between molecules and allows it to go through a bit more working before failure (cracking). Working off this as a premise, if Spyderco is grinding the scallops with the grinding apparatus under pressure then it may account to some degree for this anomalous phenomenon.
...

Interesting, thanks for sharing!

But if "grinding the scallops with the grinding apparatus under pressure" leads to the much better edge retention of SE over PE, than this should be about equally true for other steels than H1 too, right?
(THAT SE generally holds an edge longer than PE in the same steel "by orders of magnitude" (quoting Dr Larrin viewtopic.php?p=1339733#p1339733) is no secret anyway. But we are talking that this phenomenon is especially and even much more prominent when it comes to H1/H2, and that the reason is some "work hardening").

[Wartstein]

...
I was just re-reading the KnifeSteelNerds article on H1. They didn’t see increased hardness at the edge, though it does not specify PE or SE. The article theorizes the work hardening would be superficial though.

Thanks for sharing!

Here viewtopic.php?t=84207 is the related thread from 2019, very interesting and a lot of input from Dr. Larrin Thomas

[Red Leader]

I've been enjoying this conversation, and like some others, taken up an interest in the idea of an abnormally high edge retention in the H1/H2 SE steels.

From the basic reading I've done, H1/2 is not known for high edge retention. But I have questions. Do we know exactly what is causing this high edge retention in the SE blade profiles? The 'work hardening' idea just doesn't make a lot of sense to me. And how is that edge retention being determined? From what I know (not much hah), it is difficult to establish testing for edge retention on SE knives, so is it more of an anecdotal/feeling thing at this point, or has there been data captured? Have there been identical knives and grinds tested, to compare along w/ this H1, to try to flesh out if it is something with just the knife steel, or something with the process, or the geometry of the serrated edge itself?

Is the phenomenon a result of the properties of the steel, the grind process, or a little of both? How would other steels respond? If it truly is some work hardening in the grind, then I could see a knife already known for high edge retention at a higher hardness potentially responding poorly to it? But we do have some pretty comparable knives already - for example, has anyone done any in-depth testing of edge retention on something like a K390 Enuff 2 SE in comparison to this H1 Jumpmaster?

I don't doubt Eric's claim about the edge retention on the SE Jumpmaster. It's a big statement, and probably warrants some follow up information and further research. If some sort of formula not-really-explored-much is beating out the highest edge retention knife steel, it is not trivial.

Personally, I had no real interest in SE knives before reading this thread, but it (as well as Evil D's serration thread at the top of this forum) has got me really intrigued. I sense a lot of untapped potential here.

[JoviAl]

...My friend Tom who is a doctor of engineering told me that I was work hardening the steel with the hammer and causing compression and micro fracturing of the structure, but heating it to cherry red again relaxes the bonds between molecules and allows it to go through a bit more working before failure (cracking). Working off this as a premise, if Spyderco is grinding the scallops with the grinding apparatus under pressure then it may account to some degree for this anomalous phenomenon.
...

Interesting, thanks for sharing!

But if "grinding the scallops with the grinding apparatus under pressure" leads to the much better edge retention of SE over PE, than this should be about equally true for other steels than H1 too, right?
(THAT SE generally holds an edge longer than PE in the same steel "by orders of magnitude" (quoting Dr Larrin viewtopic.php?p=1339733#p1339733) is no secret anyway. But we are talking that this phenomenon is especially and even much more prominent when it comes to H1/H2, and that the reason is some "work hardening").

I don’t know if it would be the same for other steels as they generally get heat treated then ground, whereas (I may be misremembering) H1 and H2 are not heat treated, so the area of effect from the heat and pressure of the scallops being ground would be extremely localised to the edge itself.

I have no skin in the game, I’m just curious more than anything. My H1 Jumpmaster 2 still has excellent edge retention and I’ve sharpened that thing a lot, so I’d assume it is more down to the SE than the steel itself if I’m still getting excellent results after hundreds of touch ups and sharpenings. It is hard to do an apples to apples comparison as I don’t have any SE knives of the same model in H1/2 and Cru-wear or K390. The grinds are different on my Jumpmaster 2 to my Temperance SE sprint or my K390 SE Police 4 LW, so it wouldn’t really be a fair test.

Having typed all this out I think I’ve realised I’m not actually that bothered about finding out life is short and all of my Spyderco knives are pretty splendid regardless of steels, grinds and designs.

[Wartstein]

..
Personally, I had no real interest in SE knives before reading this thread, as well as Evil D's serration thread at the top of this forum. And now I'm starting to see the light. I sense a lot of untapped potential here.

Then imo it was really worth it for you to read that thread

Not only if you are looking for enhanced edge retention (which SE definitely has over PE for several reasons,and you don´t have to take my layman word for it, but rather Sals, Dr. Larrin Thomas (just scroll through the thread I linked before viewtopic.php?t=84207), and those of many others more experienced than I am), but for other superior properties (over PE) too, but to list those would be really off topic.

I just may quote Sal from another interesting SE thread (about the highly recommended Chap SE)

"The resistance to serrations in general is surprising" [Among knife buyers/users] viewtopic.php?p=1811600#p1811600
... And yes, it is, given how good SE generally (and not only for certain, limited applications) really can be.

[Red Leader]

..
Personally, I had no real interest in SE knives before reading this thread, as well as Evil D's serration thread at the top of this forum. And now I'm starting to see the light. I sense a lot of untapped potential here.

Then imo it was really worth it for you to read that thread

Not only if you are looking for enhanced edge retention (which SE definitely has over PE for several reasons,and you don´t have to take my layman word for it, but rather Sals, Dr. Larrin Thomas (just scroll through the thread I linked before viewtopic.php?t=84207), and those of many others more experienced than I am), but for other superior properties (over PE) too, but to list those would be really off topic.

I just may quote Sal from another interesting SE thread (about the highly recommended Chap SE)

"The resistance to serrations in general is surprising" [Among knife buyers/users] viewtopic.php?p=1811600#p1811600
... And yes, it is, given how good SE generally (and not only for certain, limited applications) really can be.

EDIT: In reading that entire thread back from 2019, I'm way late to the party here, but none less fascinated.

Thank you, and I appreciate your post. I think the two biggest things keeping SE knives under the radar (IMO of course) are a fear of sharpening (which I still have, though not insurmountable) and just generally the lack of SE knives in the wild. I also see a resistance among knife users who may think that the application may not be as broad - and therefore less useful. But in thinking about it, I can see how a SE knife, if given thought to specific applications, and be a more conscientious and intentional (intelligent?) choice.

Hey, as long as I have another excuse to buy a knife lol

I passed by so many fully SE K390 knives at the Seconds Sale

[Wartstein]

EDIT: In reading that entire thread back from 2019, I'm way late to the party here, but none less fascinated.

Thank you, and I appreciate your post. I think the two biggest things keeping SE knives under the radar (IMO of course) are a fear of sharpening (which I still have, though not insurmountable) and just generally the lack of SE knives in the wild. I also see a resistance among knife users who may think that the application may not be as broad - and therefore less useful. But in thinking about it, I can see how a SE knife, if given thought to specific applications, and be a more conscientious and intentional (intelligent?) choice.

Hey, as long as I have another excuse to buy a knife lol

I passed by so many fully SE K390 knives at the Seconds Sale

For pushing SE I risk going off topic a bit further, cause there is not much that puzzles me more than how persistant some "myths" surrounding SE are and thus how many people might miss out on its (imo) superior performance (in an usual EDC folder!)

- Sharpening: Actually to me even a bit quicker and easier than PE, see just the tips on the first post and the vid in this great thread: viewtopic.php?p=1349519#p1349519

- I am sure not a professional knife user, but I do use them al lot and in many applications:
To me a good (Spyderco) serrated edge works better or at least not worse in almost any EDC task than PE - the key word here is "good", "shallow", "non aggressive" SE (recommendations of which I do know that they offer that type of SE: Endela SE; Chaparral SE, Stretch XL SE; Caribbean SE (from what I hear); Rock/Leaf Jumper SE;

Add the clearly enhanced edge retention, the effectively longer cutting edge than the same blade in PE, the ability to still "work" when technically already dull: Much that speaks for giving SE a fair try!!

Here viewtopic.php?t=85045 another interesting thread about what SE can do

/ To go to "on topic" again:
Sure a serrated H1/H2 blade is something to experience too!
To me a real harder work option, for examle when cutting branches or the like - but for my taste a bit too "aggressive" teeth to be perfect for normal, lighter EDC tasks (though the teeth will mellow out with sharpening)

[zhyla]

Thanks for sharing!

Here viewtopic.php?t=84207 is the related thread from 2019, very interesting and a lot of input from Dr. Larrin Thomas

Thanks for the link. That thread has essentially no conclusion. Bunch of people saying H1 SE is magic and Larrin saying there is no magic or apples to apples data.

[vivi]

I'll say the same thing I said in 2019 even though I pretty much never carry SE any more.

Sometimes you just have to get real world experience with something.

The way things compare on paper is not always the same as how they compare when actually being put to use.

Over the years I concluded H1 ground at a very thin edge angle and given a coarse apex is pretty much the best balance for me in terms of toughness, edge holding, corrosion resistance and ease of sharpening. I haven't found anything that strikes the same balance, though I have no tried magnacut or vanax yet. I have used LC200N a lot and while I like it quite a bit H1 seems more indestructible.

What my own senses show me when I use tools will always matter more to me than on paper comparisons others make without ever using the things being compared.

[Red Leader]

I'll say the same thing I said in 2019 even though I pretty much never carry SE any more.

Sometimes you just have to get real world experience with something.

The way things compare on paper is not always the same as how they compare when actually being put to use.

Over the years I concluded H1 ground at a very thin edge angle and given a coarse apex is pretty much the best balance for me in terms of toughness, edge holding, corrosion resistance and ease of sharpening. I haven't found anything that strikes the same balance, though I have no tried magnacut or vanax yet. I have used LC200N a lot and while I like it quite a bit H1 seems more indestructible.

What my own senses show me when I use tools will always matter more to me than on paper comparisons others make without ever using the things being compared.

Curious...as someone who is contemplating getting more into SE knives, what were your thoughts regarding moving away from them? Thank you for any thoughts you have.

[Jefke]

To me a good (Spyderco) serrated edge works better or at least not worse in almost any EDC task than PE - the key word here is "good", "shallow", "non aggressive" SE (recommendations of which I do know that they offer that type of SE: Endela SE; Chaparral SE, Stretch XL SE; Caribbean SE (from what I hear); Rock/Leaf Jumper SE;

@Wartstein You don't mention what steel choice for the Endela and Rock/Leaf Jumper. VG10 or K390? Or both?

Trying serrations has been on my to-do list for a while now. I think it's time I pull the trigger on an SE spyderco. But I'm agonizing over which one to get, Leaf Jumper, Delica or Chaparral.
I know, the obvious answer is all of them , but I have to be a responsible adult and keep my financials healthy

[Wartstein]

@Wartstein You don't mention what steel choice for the Endela and Rock/Leaf Jumper. VG10 or K390? Or both?

Trying serrations has been on my to-do list for a while now. I think it's time I pull the trigger on an SE spyderco. But I'm agonizing over which one to get, Leaf Jumper, Delica or Chaparral.
I know, the obvious answer is all of them , but I have to be a responsible adult and keep my financials healthy

I actually never tried K390 (neither in PE nor SE), so I can only talk about VG10 with those choices.

That said: I´d got with VG10 (especially when it is your first experience), cause in SE it holds an edge longer than PE anyway, and is imo, while "just" decent in PE, great in SE (and easier to grind, so you can "tune" the teeth quicker to your liking, should you choose to do so).

/ As for the kind of serrations I personally feel are the best for general use: The Leaf Jumper definitely has those, but the Chaparral SE is an even better and amazing performer (I know both models from real experience)

As for the Delica SE: I´d NOT go with the VG10 version, since it only comes in sabre grind and with rather aggressive serrations.
The ffg K390 Delicas serrations look really good though.

[James Y]

@Wartstein You don't mention what steel choice for the Endela and Rock/Leaf Jumper. VG10 or K390? Or both?

Trying serrations has been on my to-do list for a while now. I think it's time I pull the trigger on an SE spyderco. But I'm agonizing over which one to get, Leaf Jumper, Delica or Chaparral.
I know, the obvious answer is all of them , but I have to be a responsible adult and keep my financials healthy

I actually never tried K390 (neither in PE nor SE), so I can only talk about VG10 with those choices.

That said: I´d got with VG10 (especially when it is your first experience), cause in SE it holds an edge longer than PE anyway, and is imo, while "just" decent in PE, great in SE (and easier to grind, so you can "tune" the teeth quicker to your liking, should you choose to do so).

/ As for the kind of serrations I personally feel are the best for general use: The Leaf Jumper definitely has those, but the Chaparral SE is an even better and amazing performer (I know both models from real experience)

As for the Delica SE: I´d NOT go with the VG10 version, since it only comes in sabre grind and with rather aggressive serrations.
The ffg K390 Delicas serrations look really good though.

You forgot to mention the VG-10 SE Endela!

Jim