Category: Steel and Knife Properties
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Knife Steels Rated by a Metallurgist – Toughness, Edge Retention, and Corrosion Resistance
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Which Quenching Oil is Best for Knives?
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YouTube
The following information is also available as a YouTube video for those that prefer watching to reading. The video might be more fun though there are more details and more discussion in the article.
LC200N/Cronidur 30 – History and Properties
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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.
Bainite Heat Treatments of 52100, O1, and 1095 – How Much Toughness?
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YouTube Video
There is a video version of the following content:
CPM-15V and the Lost CPM-20V – How Much Vanadium Can you Add?
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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
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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.
How to Heat Treat 8670
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Podcasts
I appeared on two podcasts this past week, Knife Perspective and Mark of the Maker. Knife Perspective I had been on before so we mostly focused on MagnaCut and other topics. Mark of the Maker was a full interview asking about my background before discussing my book, website, and CPM MagnaCut. So listen to one or the other or both depending on what you’re in the mood for.
CPM MagnaCut – The Next Breakthrough in Knife Steel
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CruForgeV – The Unfortunate Events that Killed a Forging Knife Steel
New Steel and New Patreon Supporters
On Patreon we now have a full set of experiments on the new knife steel I designed for Crucible and Niagara Specialty Metals. The results are extremely promising. Those results are only available on Patreon until it is time to do the formal announcement. Thanks to Chester Dussault, Bob Burland, Matt Masuda, Scott Decker, Philip Dempsey, David Heleander, ConvencienceShout, Chris Pregent, Egan, Morgan Noonan, Michal Galovič, Kumar Muthusamy, Eric Divine, Simon Moeskjær Balle, and Ben Horridge 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.
Those photos and drawings will help people understand ! Orientation – I was curious about what Crucible does with that .Their CPM goes to Niagra Metals for rolling and they cross roll the steel. Cut into squares and rolled alternating direction to minimize directional properties. I think Matt Gregory found that in his visit.
It would be interesting to test the transverse toughness of those steels for sure.