S90V and S125V – History and Properties

[Larrin]

New article about S90V and S125V, including how they were developed, toughness and edge retention, and information on heat treating them. Also, the history of these steels in knives, how knifemakers perceived the steel early on, and why they aren’t mainstream knife steel choices. https://knifesteelnerds.com/2020/09/28/ ... eat-treat/

[Pancake]

I am a simple man.
I see article from Larrin, I am happy.

[PStone]

Thanks for sharing Larrin!

Do you think the nitrogen addition to s90 should be revisited again(s90vn)? Would that make it easier to grind/work with, and therefore make it a more attractive option to more production companies?

[blues]

Good stuff, Larrin.

I had a custom Model 4 built for me by my late friend, knife maker "Kit" Carson, with S90V (then 420V) in the middle to late 90's. It was my very first custom knife...and holds pride of place in my collection.

[Larrin]

Good stuff, Larrin.

I had a custom Model 4 built for me by my late friend, knife maker "Kit" Carson, with S90V (then 420V) in the middle to late 90's. It was my very first custom knife...and holds pride of place in my collection.

Nice knife!

[Larrin]

Thanks for sharing Larrin!

Do you think the nitrogen addition to s90 should be revisited again(s90vn)? Would that make it easier to grind/work with, and therefore make it a more attractive option to more production companies?

Given that the nitrogen version had better wear resistance, at least in the crossed-cylinder test, I'm not sure if it would be easier to work with or not. If the better performance was due to carbide refinement it could be that the grindability was somewhat better. On the other hand, if it was due to more vanadium carbide (carbonitride) it could be more wear resistant and more difficult to grind.

[PStone]

Thanks for sharing Larrin!

Do you think the nitrogen addition to s90 should be revisited again(s90vn)? Would that make it easier to grind/work with, and therefore make it a more attractive option to more production companies?

Given that the nitrogen version had better wear resistance, at least in the crossed-cylinder test, I'm not sure if it would be easier to work with or not. If the better performance was due to carbide refinement it could be that the grindability was somewhat better. On the other hand, if it was due to more vanadium carbide (carbonitride) it could be more wear resistant and more difficult to grind.

Ah. That makes sense. Thanks for the reply! Great article!

[Cambertree]

Thanks for another excellent and fascinating article, Larrin.

I enjoyed reading it over the weekend, and again just now.

I was also curious about the increased nitrogen and reduced carbon version, purely from the point of view of whether it would make a better bladesteel. I was wondering if it would be possible to conjecture how it would affect the microstucture of the steel, compared to standard S90V.

But I think you’ve pretty much answered that question above.

I’m looking forward to the article on S110V. I’m also wondering if you’ll have anything more to say about the curious difference in your edge retention tests, with S90V coming in higher than S110V.

[Larrin]

In the S45VN article I wrote about nitrogen promoting vanadium carbide formation as opposed to chromium carbides. https://knifesteelnerds.com/2019/11/01/ ... 5vn-steel/

[Cambertree]

In the S45VN article I wrote about nitrogen promoting vanadium carbide formation as opposed to chromium carbides. https://knifesteelnerds.com/2019/11/01/ ... 5vn-steel/

Thanks Larrin, I hadn’t read that article yet, as I’m not so interested in S45VN, but I’ll check it out now.

[Larrin]

I will have to add a reference to it in the S90V article.

[curlyhairedboy]

Great article as usual, Larrin! It's great that you got to speak to some of the original designers.

[Larrin]

Great article as usual, Larrin! It's great that you got to speak to some of the original designers.

To learn all their secrets of steel development.

[ugaarguy]

Larrin, your timing was an excellent coincidence. I'm waiting on a dealer to ship my pre-ordered MGE distributor exclusive Native 5 LW with teal handles and S90V blade that was released last week. It's nice to see your testing back up the anecdotes that S90V has a nice balance of properties. Thank you for another very interesting article.

[Bemo]

Yes perfect timing Larrin! Really sounds like this is a good knife steel. I'm guessing the manufacturing costs associated with the grinding and polishing make other options more attractive for companies. Again, thanks Spyderco for taking on the tough jobs for us knife nerds!

[GarageBoy]

Interesting list of custom makers who used s90v

What are its advantages over s110v? Is it finer grained?

[Larrin]

Interesting list of custom makers who used s90v

What are its advantages over s110v? Is it finer grained?

The S90V came first of course so it wasn’t designed as an improvement over S110V. S110V has a finer microstructure and better corrosion resistance but more carbide. S90V has a bit better toughness and inexplicably it has better edge retention in CATRA testing.

[blues]

Interesting list of custom makers who used s90v

What are its advantages over s110v? Is it finer grained?

The S90V came first of course so it wasn’t designed as an improvement over S110V. S110V has a finer microstructure and better corrosion resistance but more carbide. S90V has a bit better toughness and inexplicably it has better edge retention in CATRA testing.

The scientific / technical term for that is called "magic". :p

[zuludelta]

I've always been curious about S90V, but find that knives made with S90V blades are prohibitively expensive, and have only handled them briefly at my local brick & mortar shop (pre-pandemic).

So thanks for another great article Larrin, I really learn a lot from the pieces you write on more exotic/expensive/hard-to-find knife steels that many of us will probably never get to use firsthand. Your work is an excellent resource for those of us who appreciate the history & science behind cutlery steel.