Model request: Enuff in S7 steel

[LosOne]

The S7 is pretty much the toughest steel around... yet there's pretty much no production knives in that steel.

Spyderco pretty much always tunes heat treat to the custom level.

Spyderco is pretty much the best knife manufacturer in my humble opinion.

The shape and grinds of Enuff models offer crazy performance. Toughness of S7 would take that to next level.

Imagine, tough yet slicey knife that's also easy to sharpen...

[Bolster]

I had to read up on S7. Larrin reports a C-Notch toughness as high as 130 ft lbs when it’s around Rc 56. Wow. On the other hand, the steel is seldom seen much beyond Rc 58, so is quite soft in comparison to other knife steels. Larrin concludes: “S7 doesn't have good wear resistance.” Sounds like a chopper steel. I notice that S5 is even tougher (peaking at 16o ft lbs!), but can be hardened higher than S7.

[Traditional.Sharpening]

Why do you feel that toughness is the most important metallurgical quality of steel in a sub 3" fixed blade? That's basically what you are saying if you feel S7 is the best suited in that role. I do not believe it would offer the best blend of the things I look for personally in a working knife. Do I believe it would be a poor choice? Not entirely but I could not argue it would offer the best blend. One thing it would have going is ease of maintennance but it would lack strength and wear resistance, both of which are important in a significant way. I'd argue for 1095 or O1 being closer to ideally suited if I had to, assuming a sensible heat treat.

[vivi]

Gotta be honest, that seems like an awful choice. VG10 at 4mm thick in a 3" long blade is already overbuilt. What would you gain from a tougher steel in that format?

Dream bigger. Forester sprint. Or maybe a Rock Salt. Darn Dao?



I've been rocking a 9" bladed S7 fixed blade from Scrapyard since the 2000's. That's more along the lines of a design that will bring out the qualities of S7.

[Doc Dan]

13C26 or better 14C28N would be a better choice because they are far tougher than 01 or 1095, as tough as 52100. However, the edge retention is better, especially on the 14C, and it is corrosion resistant. H1 is very tough, though soft and doesn't hold an edge that well. It is corrosion proof, though.

[JRinFL]

Not everything needs to be taken to extremes. Very few people can benefit from the extreme steels that excel in only one parameter.

[vivi]

Spyderco has already gone to extremes in regards to edge holding and corrosion resistance, I don't see any reason not to do the same with toughness. Just needs to be a design that would benefit from such a steel.

S7 is fun to work with. I've abused the **** out of that one I posted, having done things I wouldn't think of doing with 1095.

[JRinFL]

Spyderco has already gone to extremes in regards to edge holding and corrosion resistance, I don't see any reason not to do the same with toughness. Just needs to be a design that would benefit from such a steel.

S7 is fun to work with. I've abused the **** out of that one I posted, having done things I wouldn't think of doing with 1095.

You are correct, of course. I just find going to any extreme usually unnecessary, but they have gone far on edge retention, as you said, and all the way with corrosion resistance. So why not impact toughness? Not for me, but it'll make some very happy.

[Doc Dan]

Spyderco has already gone to extremes in regards to edge holding and corrosion resistance, I don't see any reason not to do the same with toughness. Just needs to be a design that would benefit from such a steel.

S7 is fun to work with. I've abused the **** out of that one I posted, having done things I wouldn't think of doing with 1095.

You are correct, of course. I just find going to any extreme usually unnecessary, but they have gone far on edge retention, as you said, and all the way with corrosion resistance. So why not impact toughness? Not for me, but it'll make some very happy.

It'll make them happy for a short while and then they'll complain that it doesn't hold an edge well enough, or something.

[vivi]

Not if its paired with the right design.

Pacific Salts will hold an edge better than K390 if you spend 8 hours a day working in a heavily corrosive environment.

S7 will hold an edge better than D2 if you're using your tool in a way that pushes its toughness more than abrasion resistance.

My S7 chopper has outchopped choppers in 1095, D2, M4, A2, N690, O1, 1075, etc.

The steel has its place, just like LC200N and 15V do. I wouldn't want an S7 dive knife, I wouldn't want a 15V splitting maul, and I wouldn't want an LC200N box cutter.

[Traditional.Sharpening]

Spyderco has already gone to extremes in regards to edge holding and corrosion resistance, I don't see any reason not to do the same with toughness. Just needs to be a design that would benefit from such a steel.

S7 is fun to work with. I've abused the **** out of that one I posted, having done things I wouldn't think of doing with 1095.

How much of this is the steel relative to the geometry of the knife? Have you actually compared 1095 in the same cross section/geometry?

[kerrcobra]

I would love to see a Spyderco knife in S7, but I agree with others that there are better designs it would excel in than the Enuff. I've never seen that Spyderco Forester, but that looks like an excellent candidate. Hopefully, they would use thinner stock though, if they decided to make something in S7, which would take advantage of its exceptional toughness.

S7 excels at impact toughness. I have a tomahawk from Hogue that's made of S7. It's thin, light and fast. It has excellent geometry, and it can take incredible abuse. I wouldn't sit around the campfire and try to use it for whittling or any other task that would benefit more from edge retention. Also, Scott Gossman has done a ton of work with S7 in his custom knives. He used to use it almost exclusively most notably in his Big Boar Tuskers, and those are excellent.

While I would absolutely love to see a big S7 Spyderco fixed blade, I'd be even more excited for them to use CPM 1V - it has incredible toughness in its own right, and even though it doesn't have the same impact toughness as S7, it's pretty close, and it still has decent edge retention. I've heard it has comparable edge retention to A2. Bark River makes a machete in CPM 1V, which has 1/8" stock on a 12" blade. That's pretty thin for a big fixed blade.

[kerrcobra]

Spyderco has already gone to extremes in regards to edge holding and corrosion resistance, I don't see any reason not to do the same with toughness. Just needs to be a design that would benefit from such a steel.

S7 is fun to work with. I've abused the **** out of that one I posted, having done things I wouldn't think of doing with 1095.

How much of this is the steel relative to the geometry of the knife? Have you actually compared 1095 in the same cross section/geometry?

1095 isn't particularly tough. In that regard, it doesn't even come close to being comparable to S7. Larrin has an article specifically about toughness in low alloy steels (here), and he even says in the quote below that 1095 isn't particularly tough. This article doesn't do any comparison against S7 obviously, because S7 is not a low alloy steel, but I just bring it up to highlight the point that if someone wants to do a comparison of toughness in a low alloy steel against S7, in similar geometry, 1095 is not a good choice.

"Carbides

Another factor that affects toughness is carbides within the steel. Higher carbon generally means greater amounts of carbide. Carbides are hard, brittle particles that contribute to wear resistance but are detrimental to toughness. Because of the complications with plate martensite the trends with carbide are not as “clean.” I drew in an approximate trendline, but the steels with lower carbon in solution (52100, 5160, 8670) have significantly higher toughness. And 1095 with its high carbon in solution has relatively poor toughness despite only a small amount of carbide."

Here's another article of Larrin's (here) where he does a general ranking of steels in toughness, edge retention, and corrosion resistance. S7 isn't included in the results, but if you look at the table results for the "Carbon and Low Alloy Tool Steel Ratings", you can see again that 1095 isn't very tough.

[Traditional.Sharpening]

Spyderco has already gone to extremes in regards to edge holding and corrosion resistance, I don't see any reason not to do the same with toughness. Just needs to be a design that would benefit from such a steel.

S7 is fun to work with. I've abused the **** out of that one I posted, having done things I wouldn't think of doing with 1095.

How much of this is the steel relative to the geometry of the knife? Have you actually compared 1095 in the same cross section/geometry?

1095 isn't particularly tough. In that regard, it doesn't even come close to being comparable to S7. Larrin has an article specifically about toughness in low alloy steels (here), and he even says in the quote below that 1095 isn't particularly tough. This article doesn't do any comparison against S7 obviously, because S7 is not a low alloy steel, but I just bring it up to highlight the point that if someone wants to do a comparison of toughness in a low alloy steel against S7, in similar geometry, 1095 is not a good choice.

"Carbides

Another factor that affects toughness is carbides within the steel. Higher carbon generally means greater amounts of carbide. Carbides are hard, brittle particles that contribute to wear resistance but are detrimental to toughness. Because of the complications with plate martensite the trends with carbide are not as “clean.” I drew in an approximate trendline, but the steels with lower carbon in solution (52100, 5160, 8670) have significantly higher toughness. And 1095 with its high carbon in solution has relatively poor toughness despite only a small amount of carbide."

Here's another article of Larrin's (here) where he does a general ranking of steels in toughness, edge retention, and corrosion resistance. S7 isn't included in the results, but if you look at the table results for the "Carbon and Low Alloy Tool Steel Ratings", you can see again that 1095 isn't very tough.

I'm not saying it's incredibly tough steel but the question is what happens to 1095 at the same edge geometry and cross section? ESEE doesn't seem to be going out of business from warranty claims on the Junglas...

[vivi]

I've compared knives of similar geometry in 1095 to that S7 scrapyard. It isn't close. Like comparing edge retention between 440c and ZDP289.

[Naperville]

Gotta be honest, that seems like an awful choice. VG10 at 4mm thick in a 3" long blade is already overbuilt. What would you gain from a tougher steel in that format?

Dream bigger. Forester sprint. Or maybe a Rock Salt. Darn Dao?



I've been rocking a 9" bladed S7 fixed blade from Scrapyard since the 2000's. That's more along the lines of a design that will bring out the qualities of S7.

That a really nice Spyderco fixed blade knife. I'd like to own that.

The craziest steel that I own is in a 1V bark River Machete that I keep near my desk. Never used it. The videos speak for themselves, it will take an arm off and that is what I bought it for.

[Traditional.Sharpening]

I've compared knives of similar geometry in 1095 to that S7 scrapyard. It isn't close. Like comparing edge retention between 440c and ZDP289.

Do you have any more info on the 1095 blade? Can you be more specific as to what you encountered there? The funny thing about the comparison you draw between those two steels is it means little to me as I don't expect a dramatic difference to be seen in use between those steels either. CATRA testing can only show a 2:1 difference between the lowest ranked and highest ranked steels in very controlled testing under very specific conditions.

What that tells you is that in real world use the difference would be very difficult to detect AND be certain that what you are seeing is a direct product of the steel differences rather than some other sort of influence you are observing. How were the knives sharpened? Can you be certain that what you are seeing is not just due to something like having a micro-burr present which fails immediately in use?

[vivi]

I've compared that scrapyard against over 25 different choppers over the years. Something like 5 of them were 1095. Similar geometries and sharpening methods used. Everything from Rat 9's to customs to ESEE junglass etc.

I go by real world use, not charts or catra. I can tell a massive difference in edge retention between 440 & zdp. I can tell a big toughness difference between S7 and 1095. Corrosion resistance between LC200N and VG10 is like night and day.

S7 is the real deal. It seems most in this thread want to question that? Weird. Don't see many folks going into 15V threads with a similar attitude.

One day I'm going to get a custom axe made out of it.

[kerrcobra]

I think he/she is just a pedant. A look at their post history confirms as much.

In regards to S7's toughness, I recall that Scott once shot one of his knives with a .41 Magnum. IIRC it bent the blade near the edge, but the second shot at that hit the spine hardly deformed it. Even at the edge though, the steel held up and didn't fracture.

[Traditional.Sharpening]

I've compared that scrapyard against over 25 different choppers over the years. Something like 5 of them were 1095. Similar geometries and sharpening methods used. Everything from Rat 9's to customs to ESEE junglass etc.

I go by real world use, not charts or catra. I can tell a massive difference in edge retention between 440 & zdp. I can tell a big toughness difference between S7 and 1095. Corrosion resistance between LC200N and VG10 is like night and day.

S7 is the real deal. It seems most in this thread want to question that? Weird. Don't see many folks going into 15V threads with a similar attitude.

One day I'm going to get a custom axe made out of it.

You haven't answered how you are sharpening in the sense of what you are using and the procedure along with what level of sharpness/deburring you accept as 'sharp'. This alone can make an enormous difference. I am not arguing S7 is a poor choice but I do question how much worse you feel 1095 is in your opinion.

How can you tell a big difference? What are you seeing exactly? How can you tell a massive difference in 440/189? Are you running trials and doing some sort of blinding to make sure that the results are not biased in some way where you are simply seeing what you expect to see?

You likely aren't seeing people asking about this sort of thing in the 15V thread because very few people have ever done this sort of thing when someone makes a strong claim to performance superiority. People simply prefer fantasy over raw data and will go on emotion versus logic. 15V has been heavy on the hype train recently and anyone who goes against this is just asking to get berated in some way and I've certainly seen at least a couple cases of that.