AR-RPM9 Knife Steel Is Not Powder Metallurgy

maybe the rare earth element is the friends we made along the way

always appreciate your detailed explanations. you sir are an asset to the knife community thank you

We're so lucky to have a metallurgist in the community that wants to spread correct information

Great info! Thank you so much for doing the detective work for us on this steel.

I always just assumed rare meant undercooked.

You seriously earned the Nerd part of Knife Steel Nerds in this video. Not just a deep dive, but an indignant and pedantic quality about the deep dive that made the inner nerd in me smile.

It sounds like the marketing team got the spec sheet for the steel and knew zero about what any of it meant and started using the Google machine.

As a Chinese, this naming really sounds like a direct translasion from Chinese words by a translator who is not familiar with metallurgy. My bladesmith friends in China told me that there is a new powder metallurgy steel available, and by watching your video, I guess that steel is this AR-RPM9 knife steel. I'm not sure about the pricing of this AR-RPM9, but that steel and the China made M390 you mentioned are very cheap in China (20 to 50 bucks for a decent bushcraft knife), with relatively good mechanical properties. Anyway, great video, and hope bladesmiths can make great knifes with this steel!

Dammmmmnnn, now this is a can of woopass. I am so glad you are doing these.

Daaaaammm!!! We’ve never been as excited about AR-RPM9 mostly because it’s been exclusive to the brand and it never seemed like anything special. Very thorough video, thank you Larrin

Great video! As my old English teacher would say, “You are being clear and concise.”

AR-RPM9 came out during the Covid lockdown. Everything was about budgets, and getting the best bang for the buck. In the knife community, all the social media testings were showing that basically anything below 9Cr isn't worth your time. So I always assumed that AR-RPM9 was just an amalgamation of a bunch of knife steel buzzwords to boost sales. It sounds scientific-y, CPMish, and it's got a 9.

Just recently started getting into knives after years of trepidation over this exact concern: there is so much wriggle-room for companies to falsely advertise the properties of steels. I'm glad that the science around steel properties is common and solid nowadays. I'm even more glad that guys like you are doing amazing work investigating the truth behind these claims about steel. You're awesome!

With the way that CJRB position and price their products, this is probably the "mystery steel" with the highest public exposure (outside of "Damascus", of course). Thank you for this desperately needed public service.

Thank you so much for this 🙌

Thanks for this, it means a LOT to the knife community.

This sounds like the marketing material was written by the marketing department only, with no input from the materials scientists and engineers involved.

I'd written it off as 9Cr when it was announced but I never actually read the name. That's hilarious.

I ❤ 440C & 1095 To me, they are true value steels, especially when done right.

Crazy that both 154CM and CPM-154 performed basically the same in your tests! Great info and thanks for your research on "RPM9"!