XHP Steel – History and Properties

[Larrin]

New article about the history of how XHP steel was designed. Also information about the general properties of XHP and how they compare to other knife steels like toughness, edge retention, and corrosion resistance. https://knifesteelnerds.com/2019/07/29/ ... roperties/

[Deadboxhero]

That's interesting how it smokes 40cp. I was surprised that the Carbides in 40cp were bigger, I would have assumed that the xhp would have bigger carbides.

[TomAiello]

Really interesting.

I was surprised by the comparison to s30v and s35vn. I wonder if my experience with XHP (mostly in the Chap) has biased me toward it unreasonably? The chap has such great geometry that it might be making the XHP look better (to me) than it warrants?

Does anyone happen to have toughness numbers for Sleipner? Has Larrin written that somewhere?

[Pancake]

Larrin, excelent job as always. Very nicely written.
Just a question, are you going to make an article about some crazy high vanadium steels like 10V ?

[ChrisinHove]

Great stuff, thank you!

[Larrin]

Larrin, excelent job as always. Very nicely written.
Just a question, are you going to make an article about some crazy high vanadium steels like 10V ?

This article talks about the history of 10V: https://knifesteelnerds.com/2018/08/20/ ... etallurgy/

I have most/all of the background I need to write articles about S90V, 15V, and carbide replacement high speed steels like Maxamet and Rex 121. Mostly waiting on toughness results to write them. I know at the very least those three articles will be written eventually.

[Larrin]

Really interesting.

I was surprised by the comparison to s30v and s35vn. I wonder if my experience with XHP (mostly in the Chap) has biased me toward it unreasonably? The chap has such great geometry that it might be making the XHP look better (to me) than it warrants?

I'm not sure what your experience has been. Estimating edge retention based on carbide fractions would put XHP edge retention right around S30V/S35VN and the experimental results show the same thing. With XHP and S30V being so close, hardness and edge geometry are likely to explain any differences outside of personal bias.

Does anyone happen to have toughness numbers for Sleipner? Has Larrin written that somewhere?

I wrote about the history of Sleipner in this article: https://knifesteelnerds.com/2019/06/03/ ... uff-steel/
The toughness is probably a little bit better than conventional CruWear, and significantly worse than CPM CruWear. Uddeholm doesn't rate its toughness as particularly high in its documents: https://www.uddeholm.com/app/uploads/si ... 19-e15.pdf

[SpyderEdgeForever]

This is amazing, along with the other knife articles/papers you write, Larrin. Thank you! I for one have great admiration and appreciation for you and your work, friend.

I have a question about this:

How much difference could there be if two notable knife companies (I won't say the names) both produce quality folders or fixed blades from this steel? Can we assume that if they have good quality control the basic properties would remain pretty much the same, or, could they vary greatly?

[TomAiello]

Thank you, Larrin!

[Naperville]

Thank you for the article Larrin. I read every bit of it, and will reread it. CTS-XHP is one of my favorite steels and I was really miffed when Cold Steel dropped it. Whoever manages the production of CTS-XHP, they goofed in getting the steel out the door to manufacturers.

[Larrin]

This is amazing, along with the other knife articles/papers you write, Larrin. Thank you! I for one have great admiration and appreciation for you and your work, friend.

I have a question about this:

How much difference could there be if two notable knife companies (I won't say the names) both produce quality folders or fixed blades from this steel? Can we assume that if they have good quality control the basic properties would remain pretty much the same, or, could they vary greatly?

You should read this: https://knifesteelnerds.com/2019/07/01/ ... cannot-do/

[Halfneck]

I've always liked CTS-XHP steel, very cool to read about it.

[Pancake]

I have most/all of the background I need to write articles about S90V, 15V, and carbide replacement high speed steels like Maxamet and Rex 121. Mostly waiting on toughness results to write them. I know at the very least those three articles will be written eventually.

Thank you Larrin. Sometimes I forgot that I have read about some steel.

Really looking for the HHS steels article, keep up the great work!

[Baron Mind]

While xhp has similar wear resistance to s30v and s35vn, I think the reason users experience greater edge retention in use has to do with xhps higher hardness. Being harder gives it greater strength, and makes the edge less likely to roll or chip.

[Bloke]

Thanks Larrin! :)

[Pelagic]

Thank you for the article Larrin. I read every bit of it, and will reread it. CTS-XHP is one of my favorite steels and I was really miffed when Cold Steel dropped it. Whoever manages the production of CTS-XHP, they goofed in getting the steel out the door to manufacturers.

Yep, honestly that was one of the best things about Cold Steel. RIP

[Larrin]

While xhp has similar wear resistance to s30v and s35vn, I think the reason users experience greater edge retention in use has to do with xhps higher hardness. Being harder gives it greater strength, and makes the edge less likely to roll or chip.

S30V and S35VN can get to 63-64 Rc if desired. I don’t know what typical production hardness differences are between S30V and XHP, however.

[JD Spydo]

Glad you brought this XHP steel up Larrin :) I have a C-36 Military model with XHP as a backup to my M390 unit. I had suspected for a long time that XHP might just be a great steel for serrated edges. After using one of those COLD STEEL models serrated with XHP blade steel it reminds me a lot of the endurance that the old 440V ( S60V) has with serrated edges ( really good).
I don't rate in the top 5 for plain edges but I do put it in the top 10 though.
Again another great thread Larrin.

Also is there a good scientific way to rate blade steels for serrated edge performance? I've just been rating them myself by my own personal uses and have come up with some interesting results. I've found that few blade steels seem to perform really good in both edge types. What say you?

[Larrin]

Also is there a good scientific way to rate blade steels for serrated edge performance? I've just been rating them myself by my own personal uses and have come up with some interesting results. I've found that few blade steels seem to perform really good in both edge types. What say you?

I don't have enough data on serrated edges to do a rating. I only have one or two examples of serrated edge CATRA testing and those barely saw any wear over the duration of the test. I suspect CATRA testing of serrated edges is primarily controlled by the edge geometry rather than steel.

[jimmd]

Some of my favorite knives have CTS-XHP: Koenig Arius, Thorburn L51C, and Spyderco Chaparral. I don't get too worked up regarding steel types, but I like it. I'd be happy to see it on more Spydercos.