I Tested the Edge Retention of 48 Steels

am now a patron (finally) thanks so much Larrin!

Biggest thing that stuck out to me was...

I never really clearely understood why someone would choose a stainless over a non-stainless tool steel... but in the testing (of both toughness and edge retention) the non-stainless tool steels have higher capability (higher edge retention and greater toughness) as a groupl. Good to see this documented across a broad number of steels.
 
@not2sharp
There are a lot of modern steels that can run 60rc without significant loss of toughness and can even be tougher than other steels at 55hrc.

HRC will not tell you all the mechanical properties of a steel. Structures and features that make a steel tougher and more durable don't show up when testing HRC although there is a link between raw toughness and lower hardness just like higher hardness and wear resistance but on the chart you can also see the higher HRC doesn't always mean it more wear resistant. Carbide volume and type is significant.


An an extreme example of this effect but in opposite would be Rex121 at 55rc which will likely have lower impact toughness than 8670 at 60hrc due to the higher carbide volume dropping the impact toughness/shock resistance.

So if raw toughness is the ultimate goal I'd pick a steel that dumps the carbide volume, remove the less desirable features in the Microstructure with a bomber HT with solid time and temp selection and execution and you can rock 60rc all day for higher toughness operations given sufficient geometry.

The graphs in the article should show you that everything is a trade off and the wonderful complexity of it all. It never gets old, always more things to play with.

55rc is not realistic or desired for a quality cutting knife with a small thin blade.

55rc would limit the geometry since it's not strong enough to support a more desirable thinner geometry. The edge at 55rc will be more difficult to deburr, it will roll and blunt smooth faster in use. A small knife is also unlikely to be swung like an axe to see any benifit of the added shock resistance. Mostly folks just want an edge that doesn't chip and shock resistance isn't the only factor for that either.

I'd invest less in a specific HRC applied to ALL STEELS and invest more into understanding the features each steel can offer.

Lots of other cool articles to read on knifesteelnerds.com to build a solid foundation of knowledge if you want to go further down the rabbit hole. :D

-Shawn





That was an excellent read. My only question would be regarding the hardness target. Typical knife harness tends to be in the mid 50s(RC), especially for fixed blades. Was there any particular reason for testing at 60+, and would you expect a significant change in ranking performance if the test had targeted 55RC?

n2s
 
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I've only skimmed the article so far, but if I understood it correctly Larrin Larrin : you've once again proven that ZDP-189 is the best knife steel and that all knives henceforth should be made of it? Fantastic! Thanks so much for your hard work.
 

Stealers
Steeler's Wheel?

From the Book of Laminations:

Shawn to the left of me, Larrin to the right,
Here I am, stuck in the middle with you.
 
Do you have any equivalents of either the Victorinox steel or 12c27 on the edge retention comparison? Thanks!
 
I'm going to sleep at a Holiday Inn tonight and try again to read it in the morning. I expect total enlightenment about 9am tomorrow.

Thank you for all your hard work Larrin Larrin :thumbsup:

I look forward to your 48 youtube videos of you batoning your rectangular knives. Us knife nerds know that is the real test.
 
Do you have any equivalents of either the Victorinox steel or 12c27 on the edge retention comparison? Thanks!
The closest is AEB-L though 12C27 would be somewhat worse.
 
Thank you Larrin and DeadboxHero, and please extend our thanks to Mrs. Larrin as well.

I do like to nerd out on this stuff now and then.

While it hasn't changed my mind on my choices really, It certainly is nice to put data behind them.
 
Maybe I missed something but is s30v not proven to be a spectacular steel for the price/availability?
 
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