New Knife Steel Ratings by Knife Steel Nerds

[Larrin]

I have a new article and video with knife steel ratings in terms of toughness, edge retention, and corrosion resistance. Plus discussion of how those ratings are generated and the steel factors that control them. The video and article are complementary I recommend reading/watching both.
Video: https://youtu.be/dg4qcdDba9w
Article: https://knifesteelnerds.com/2021/10/19/ ... esistance/

[Wartstein]

Thanks Larrin!!

I'm really looking forward to reading / watching this as soon as I get home today! Can't wait actually.

[SG89]

Really neat info.

[Ramonade]

Thanks for sharing it here too. I hope it won't influence me too much towards/against some steels !
(Like every other articles have done in the past )

[z1r]

Me too, thanks. A cursory look and it seems that I was right in questioning whether I needed an S110V N5 since I already have an S90V. Doesn't seem like it offers any real improvement so I'll spend the money on a ZDP Stretch 2 instead.

Also makes me question passing on a knife in M4 since I have the same knife in Rex45. Thinking I will want that M4 now!

[TomAiello]

Me too, thanks. A cursory look and it seems that I was right in questioning whether I needed an S110V N5 since I already have an S90V.

Spyderco's s110v has been substantially more stain resistant than Spyderco's s90v, in my uses. I prefer s90v for general use, but if I'm doing something where corrosion resistance is also important, I might opt for s110v.

[sakana-sensei]

So basically I need Vanax, and I also need to apologize to Vanax for thinking it was a prescription drug for anxiety. That Magnacut sounds really interesting too.

Drats, and I just dropped a couple fat Benjies on the Spydiechef too. (No regrets though)

[zuludelta]

Great article, the ratings charts are a very handy quick-reference guide. And it definitely gives me a lot of food for thought when I consider the cost of knives—am I paying for the steel's potential performance? The assurance of a company who does a consistently good heat treat? The knife's overall design?

And great video as well... I got a good chuckle out of the Mr. Rogers format, that was Cedric & Ada-levels of knife community comedy.

[Wartstein]

I am - again - surprised how relatively "bad" REX45/HAP 40 fares. Especially how really not spectacular its toughness actually is. Of course I don't doubt the results at all (!), but this is different to what - also experienced - knife users always tend to say and also different to my own experience.
M4 seems to be the clearly better choice here: About the same edge retention, noticeable tougher.

And: LC200N: Amazed by its very high toughness!! Very cool.
On the flipside I wonder again how pretty often I heard something along the lines that LC200Ns edge retention would be "between VG10 and S30V", when in fact its below VG10 and even BD1N according to the data (this is also my - totally layman! - experience).

[Larrin]

I am - again - surprised how relatively "bad" REX45/HAP 40 fares. Especially how really not spectacular its toughness actually is. Of course I don't doubt the results at all (!), but this is different to what - also experienced - knife users always tend to say and also different to my own experience.
M4 seems to be the clearly better choice here: About the same edge retention, noticeable tougher.

And: LC200N: Amazed by its very high toughness!! Very cool.
On the flipside I wonder again how pretty often I heard something along the lines that LC200Ns edge retention would be "between VG10 and S30V", when in fact its below VG10 and even BD1N according to the data (this is also my - totally layman! - experience).

The ratings for Rex 45 are brought down some by the fact that it is used at high hardness only. But even if it was 62 Rc CPM-M4 would be both more wear resistant and tougher.

[Naperville]

Thank you for pointing out that 420HC has poor edge retention. I'll stick with Spyderco's 4V fixed blades. I was looking at a Buck 916 Bowie Knife but forgetaboutit! I'll buy a 2nd Province in 4V, which was my initial plan.

LUV ME SOME 4V!

Thanks @Sal!!!

[z1r]

Really appreciate the article and input. Shoulda pulled the trigger on that M4 when I had the chance.

What actually surprised me was how well 8Cr13MoV faired. It gets so much crap talked about it but it holds an edge so much better than many HC steels and is definitely more corrosion resistant. And, in the Spyderco lineup, it's very affordable.

[metaphoricalsimile]

Am I missing something or is K390 not included in the ratings?

[metaphoricalsimile]

I'm also curious where BD1N gets its toughness rating from when I've never seen it rated for toughness in any of your articles.

[zuludelta]

What actually surprised me was how well 8Cr13MoV faired. It gets so much crap talked about it but it holds an edge so much better than many HC steels and is definitely more corrosion resistant. And, in the Spyderco lineup, it's very affordable.

I think otherwise decent, affordable steels like AUS-8/8Cr13MoV and 440C develop a bad reputation partly because the market is flooded with cheap knives in those steels that have been poorly heat-treated or have really terrible edge geometry.

Spyderco does a good job with its 8Cr13MoV knives, but there are so many companies out there that regularly pump out 8Cr13MoV knives with edges that are ground terribly, & therefore not giving the steel the chance to perform anywhere close to its potential.

[Fireman]

Thanks Dr. Larrin. I need to contribute to your Patreon this Christmas

https://www.patreon.com/Knifesteelnerds

You the man!

[ZrowsN1s]

I am - again - surprised how relatively "bad" REX45/HAP 40 fares. Especially how really not spectacular its toughness actually is. Of course I don't doubt the results at all (!), but this is different to what - also experienced - knife users always tend to say and also different to my own experience.
M4 seems to be the clearly better choice here: About the same edge retention, noticeable tougher.

And: LC200N: Amazed by its very high toughness!! Very cool.
On the flipside I wonder again how pretty often I heard something along the lines that LC200Ns edge retention would be "between VG10 and S30V", when in fact its below VG10 and even BD1N according to the data (this is also my - totally layman! - experience).

The ratings for Rex 45 are brought down some by the fact that it is used at high hardness only. But even if it was 62 Rc CPM-M4 would be both more wear resistant and tougher.

Makes me wonder how much some of my feelings about steel performance are in my head. I've always loved M4, but would have sworn my Rex45 Para3 out performed my M4 para2.

[zuludelta]

And: LC200N: Amazed by its very high toughness!! Very cool.
On the flipside I wonder again how pretty often I heard something along the lines that LC200Ns edge retention would be "between VG10 and S30V", when in fact its below VG10 and even BD1N according to the data (this is also my - totally layman! - experience).

LC200N's toughness can maybe help explain the common misconception regarding its edge retention. Because it's very tough, it can be sharpened to a very thin, acute edge while still having great edge stability.

In "real-world" use, that may mean that you can sharpen a 59 HRc LC200N knife to 12° per side & still have a stable edge, and at that geometry, it will probably outcut a similarly-stable & similarly hard VG-10 edge sharpened at 20° per side.

[Wartstein]

..

LC200N's toughness can maybe help explain the common misconception regarding its edge retention. Because it's very tough, it can be sharpened to a very thin, acute edge while still having great edge stability.

In "real-world" use, that may mean that you can sharpen an LC200N knife to 12° per side & still have a stable edge, and at that geometry, it will probably outcut a similarly-stable VG-10 edge at 20° per side.

That´s actually a great point! Should have thought of this myself.

I had no idea till this thread how extremely tough LC200N really is - especially compared to other steels with similar edge retention it seems to be in another league concerning toughness.

This and your input really motivate me to give my LC knives a really acute edge (well, I actually have just two - Salt 2 SE / Waterway). Should work out just fine, and increase the edge retention by a lot.

Since corrosion resistance is no concern of mine, 14C24N is another steel I might have to look into! (Unfortunatley not available in a Spyderco). According to the charts even a bit tougher than LC, while having about the same edge retention (and actually still pretty high in corrosion resistance, though not as high as LC)

[Karl_H]

I am - again - surprised how relatively "bad" REX45/HAP 40 fares. Especially how really not spectacular its toughness actually is. Of course I don't doubt the results at all (!), but this is different to what - also experienced - knife users always tend to say and also different to my own experience.
M4 seems to be the clearly better choice here: About the same edge retention, noticeable tougher.

…

I think Spyderco ran their Rex 45 too hard. Larrin tried to replicate the Spyderco heat treatment, which basically means that it wasn’t tempered for long enough to achieve an more optimal level of toughness. Tempering REX45 to 64-65 HRC would have resulted in a better balance of properties, in my opinion. If Larrin ever decides to optimize the heat treatment for REX 45, I think you will see a more desirable balance of properties.

I think most Japanese knife makers that use HAP40 (Hitachi equivalent of REX 45) temper it down to about 65 HRC. So, Spyderco’s heat treatment is going to result in much lower toughness than what is commonly achieved with the steel, and I have no idea why they decided to do that.