Category: Steels
4 thoughts on “Steels”
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H2 Steel – H1 the sequel
Background
A recent Spyderco Byte has announced a replacement for H1 steel – H2. H1 is known for being a very high corrosion resistance steel used primarily in Spyderco’s Salt line of knives. I have a previous article about the design of H1 and how it “works” which you can read here. I am somewhat tempted to re-write large chunks of that article here because H1 is one of the most misunderstood knife steels but I am going to try to hit a few of the highlights without much explanation and I hope you will read the earlier article to understand what I am referring to:
Wood Knife that is 3x Sharper than Steel? Spoiler: No
Several people have sent me links to a recent publication about a process that increased the hardness/strength of basswood. They then demonstrated the success of their processing by making a knife and a nail out of the wood. See here for an example of one of these articles: https://www.cnet.com/news/scientists-create-a-wooden-knife-thats-three-times-sharper-than-steel/
Laboratory Development of ApexUltra Forging Knife Steel
Note: I have a new article on ApexUltra that shows properties of the final product (as opposed to these experiments with “lab scale” production). And also heat treatment recommendations on the final steel. Click here to read the newer article.
LC200N/Cronidur 30 – History and Properties
Thanks to Maxi, Michael Fitzgerald, Samy Tammam, Russ Ramski, and Scott Guthrie for becoming Knife Steel Nerds Patreon supporters! We are almost to 300 supporters! Wow!
New T-Shirts!
After requests from any kind fans we now have t-shirts available, including an awesome one with the MagnaCut logo on front and knife grinding man on the back. Note it is available in a few different styles and colors. Click this link if you want one.
CPM-15V and the Lost CPM-20V – How Much Vanadium Can you Add?
Thanks to Tim Marais, Daniel DeRosia, Jess Hoffman, David Rogers, Mo, John Macklis, and R. Thomas Buffenbarger for becoming Knife Steel Nerds Patreon supporters!
History of CPM-15V
CPM-15V is essentially a higher vanadium extension of CPM-10V developed by Crucible steel in the late 1970s. I wrote about the history of CPM-10V in this article so I won’t copy-paste all of that here. Prior to powder metallurgy technology it was known that adding higher vanadium would lead to greater wear resistance due to the very high hardness of vanadium carbide. However, once the vanadium content exceeded 4-5% the carbides would be large enough that the steel would fail in forging, and toughness would also be reduced. So the highest wear resistance steel for many years was T15 high speed steel with ~5% vanadium. With CPM-10V they saw what the limit was for vanadium additions and found that once they reached about 11% vanadium the carbide size would be increased because the vanadium carbides would form in the liquid steel before the steel could be gas atomized into powder. Read about the powder metallurgy process in this article. The more vanadium that is added the higher the temperature where the vanadium carbides form. When the formation temperature is higher than the temperature of the liquid steel then they form prior to atomization giving the large carbides in the 11% vanadium PM steel below (labeled CPM 11V):
Edge Retention Testing of Seven More Steels – XHP, SPY27, Maxamet, Rex 45, 420, T15, Rex 76
Thanks to Knife Thoughts, Nicholas Rossi, Jason D. Stone, and Ken McCurdy for becoming Knife Steel Nerds Patreon supporters!
Update 1/5/2024: I neglected to mention in the original writeup of this article that the Z-Max was retested along with the new Maxamet and Rex 121 tests. The total cardstock cut was updated from 909 in the original testing to 948 mm.
CPM MagnaCut – The Next Breakthrough in Knife Steel
Thanks to Saptak Dutta, Bill Clancy, Cap Hayes, Electro_Static, Coll Gomila, Kody Ekstrom, Nico, Tom Ewing, Ken Johnson, Brent Stark, Jesse Warren, Malachi Chou-Green, Luke Haag, Bill Harrison, John Geelhoed, and Julian Hamilton for becoming Knife Steel Nerds Patreon supporters!
Matrix Steels – YXR7, CPM-1V, Caldie, and More
Thanks to Scott Larimore, Ryan Davis, David Mullin, Andrew Lutomirski, Nathan Thurman, Brome McCreary, Anthony Smallwood, Leitgeist, and Mike Walton for becoming Knife Steel Nerds Patreon supporters! On Patreon we now have four updates about an upcoming new knife steel with very promising results.
Vanadis 8 – Better than CPM-10V
Thanks to Will and Justin Mann for becoming Knife Steel Nerds Patreon supporters!
My book Knife Engineering is available for Christmas and Hanukkah presents.
History of Vanadis 8
The history of Vanadis 8 goes back a lot further than just the steel itself, really we have to know the history of 10V to know all of the background that is relevant. You can read about CPM-10V in this article. CPM-10V is important because Vanadis 8 is intended as a replacement for CPM-10V, or at least for similar applications. CPM-10V was developed by Crucible in the late 70s, as the first powder metallurgy steel to utilize a microstructure made up of only vanadium carbide, as opposed to chromium and molybdenum/tungsten carbides. This gave 10V a combination of good toughness along with very high wear resistance from the ~10% vanadium and therefore ~17% vanadium carbide.
CPM-S110V Steel – History and Properties
Thanks to Aaron @ Gough Custom, Aaron McVay, Mark Scott, Jeffrey St. Claire, Grant Seim III, and saiiiiiii1 for becoming Knife Steel Nerds Patreon supporters!
I’m eventually going to stop plugging my book Knife Engineering in every new article, but that day is not today. Go buy one for yourself, and everyone you know, as a Christmas present.
Thanks for what you are doing. There is so much misinformation, hyperbole, and exaggeration being presented as fact on the internet regarding knife blade steel. I felt like the skies cleared when I discovered your site. I really appreciate your science-based approach to demystify so many issues.
Thanks!
Can you tell me about AR-RPM9 please?
Thanks,
Mine S
I’ve only written about AR-RPM9 in an article exclusive to the Knife Steel Nerds Patreon.