Spyderco Forums

There has been some question about whether CATRA is a useful test for actually predicting the edge retention of a knife. After all, it is a test performed by a robot, not a human, and the knife cuts cardstock with sand in it, which doesn't seem like a very realistic material. So I took three big dat...

To clarify one thing, those carbide values are experimentally reported not calculated (though calculating them is also possible). Each steel has a "Ref" number that gives a reference at the bottom of the article.

For those who are interested, here are the articles: http://www.hefajstos.agh.edu.pl/files/%5B2006%5D%20Carbon%20nanotubes%20in%20an%20ancient%20Damascus%20sabre%20-%20M.%20Reibold.pdf http://www.hefajstos.agh.edu.pl/files/[2009]%20Discovery%20of%20Nanotubes%20in%20Ancient%20Damascus%20-%20Marianne%...

I’ve read the journal articles claiming carbon nanotubes in steel. They have no good evidence.

awa54 wrote: ↑

Mon Feb 04, 2019 4:58 pm

another take on damascus, possibly at odds, or maybe complimentary?

https://skullsinthestars.com/2011/09/01 ... echnology/

I don't buy the carbon nanotubes information and either does Verhoeven: https://www.nature.com/news/2006/061113 ... 13-11.html

A review of a new book from Dr. John Verhoeven about the work performed on solving the mysteries of wootz damascus. It's a fun little book. If you want to learn more you can read the review. https://knifesteelnerds.com/2019/02/04/book-review-damascus-steel-swords-solving-the-mystery-of-how-to-make-t...

Spyderco owns a Q-fog corrosion tester: viewtopic.php?t=33139#p425334

It would look something like this: https://www.q-lab.com/products/q-fog-cy ... og-ssp-cct

That was a great read, thank you for your efforts. I enjoy my 52100 Paramilitary 2 more than any of my others that are in lots of different steel variations. The 52100 has a unique toothy edge even when sharpened to a very high-grit low-micron mirrored finish. Some other steels require much lower g...

I wrote about 52100, including when the steel was invented, why it is alloyed with chromium, and how its properties compare to other knife steels. https://knifesteelnerds.com/2019/01/28/ ... 100-steel/

Here are catra results from Bohler-Uddeholm, though all competitor steels are listed under composition names, so 3V is listed under 7.5-1.3-2.75 CrMoV. S30V, 154CM, and S35VN are on there along with several BU steels. https://knifesteelnerds.com/wp-content/ ... -CATRA.pdf

Excellent study, Larrin, I love these scientific research projects that address and sometimes disprove our common assumptions. The challenge with sharpness testing like this is that if you haven't entirely removed a wire or foil edge you'll get a very different reading at the points that are tested...

I did a small study on the effect of acidic food on sharpness. This has been a commonly debated topic among kitchen knife enthusiasts. Is a carbon steel knife going to do okay with lemon juice? https://knifesteelnerds.com/2019/01/21/does-acidic-food-affect-edge-retention/ I was also interviewed on t...

Joseph08 wrote: ↑

Wed Jan 16, 2019 5:24 am

I would suggest you the https://swordsswords.com/big-bowie-stai ... knife.htmlDurable and strongly rust-resistant.

How have you made it to 31 posts while sharing spam links?

Sorry maybe a dumb question here... But is there a reason they can't completely 100% replace Carbon with Nitrogen? Maybe I'm misunderstanding things but if you could completely remove carbon would you be able to remove any possible pitting from corrosion? In the Vanax patent they found that leaving...

The obvious choices that we all have had experience with are H-1 and LC200N. I was told some time back that there is a steel called Cowry X that is supposed to have good corrosion resistant properties. Also is it safe to assume that nitrogen based steels in general all have good corrosion resistant...

Doc Dan wrote: ↑

Tue Jan 15, 2019 12:07 am

Why would 14C28N have better corrosion resistance than BD1N?

Part of the reason is the recommended austenitizing temperatures. 14C28N is higher. BD1N also has higher carbon.

ferider wrote: ↑

Mon Jan 14, 2019 8:02 pm

Your data in a chart, Larrin, hope you don't mind.

That looks nice. I only provide emotionless numbers. You shouldn’t call it PREN Acetic though as it is not a pitting resistance. Call it Cr-eq Acetic or something,

Don't mean to argue, Larrin, have wondered about these PREN indicators before ..... The Maxamet W contents in the table is not what I see on Carpenter's website ( https://www.cartech.com/en/product-solutions/cartech-micro-melt-maxamet-alloy ). Per Carpenter, it has 13% W, and - for example - the Pi...

steeljustice wrote: ↑

Mon Jan 14, 2019 3:26 pm

LC200N C 0.38 Cr 15.08 Mo .95 N .50 Mn 1.00

Cronidur30 C 0.25 to 0.35 Mn 1.00 Si 1.00 Cr 14.0 to 16.0 Mo 0.85 to 01.10 Ni .50 N 0.30 to 0.50

I believe you meant to put 0.30C and 15.0Cr unless you have a different composition than the datasheet that you are referencing.

Thanks for the great article, Larrin. I have a question: how do your PREN approximations .... - Acetic acid = Cr + 0.45(Mo + 0.5W) - Aqua-Regia = Cr + 0.79(Mo + 0.5W) - Pitting potential = Cr + 2.6(Mo+0.5W) ... work for steels with very high Tungsten content ? For example, CPM Rex 45 with 6.25% W, ...