Niobium-Alloyed, Nitrogen-alloyed, Super Steels

CPM SPY27 Experiments – Toughness, Corrosion Resistance, and More

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I have a new CATRA edge retention testing machine. I will be posting results as they come in to Patreon and articles summarizing the tests will come later to this website. If you want to see tests as they are completed come join us on Patreon. read more

Heat Treating and Processing, Steel and Knife Properties, Super Steels

Friction Forged Knives – Diamondblade Friction Stir Processing

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Friction Forged Knives

The company DiamondBlade Knives produces knives with friction stir processed (FSP) edges [1]. Diamondblade Knives is a sub-company of Knives of Alaska. They use conventional D2 tool steel and process the edge so that it has hardness of around 65-69 Rc and a spine at 38-42 Rc. The knives are advertised as having a finer grain structure than powder metallurgy stainless steel and superior edge retention, toughness, and sharpness than knives tested in 12 other blade steels including S90V. And that the friction forged edge is stainless unlike conventionally processed D2. So I am going to detail the process used to produce the knives and what the properties of the steel likely are. read more

Corrosion Resistance, Super Steels

ZDP-189 and Cowry-X – Super Steel or Overrated?

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ZDP-189 and Cowry-X

ZDP-189 is a steel produced by Hitachi and Cowry-X is produced by Daido. I have not been able to find much background information on the development of these steels. Sal Glesser of Spyderco reported he first heard about ZDP-189 around the year 2000 [1], and the earliest reference I have found to Cowry-X on Bladeforums in 2001 [2]. So both of the steels have been around for some time. The fact that two companies released essentially the same product perhaps indicates that the steel was not patented, which means little information would be available about its development. Both steels have an interesting composition with 3% carbon and 20% chromium along with a few other small additions. There are a few different reported compositions for ZDP-189 in terms of the Mo, V, and W content but below is from Spyderco. read more

History - Articles - Books, Super Steels

Super Hard (70 Rc) High Speed Steels – Maxamet, Rex 121, and More Explained

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Super Hard High Speed Steels

The super hard high speed steels (>68 Rc or so) are interesting from the standpoint of knife enthusiasts and knifemakers, particularly since knives are so often produced in the 58-61 Rc range. The metallurgy of these types of steels is also interesting. But before we get to what exactly these steels are and how they work, it makes sense to look at what led to their development first. read more

Heat Treating and Processing, Nitrogen-alloyed, Toughness

Nitro-V – Its Properties and How to Heat Treat It

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Nitro-V Steel

Nitro-V is a stainless steel sold by New Jersey Steel Baron which was first released in 2017 [1]. The steel was designed and produced in collaboration with Buderus Steel as a version of Uddeholm AEB-L modified with nitrogen and vanadium. Another obvious comparison is with 14C28N which was designed as a version of 13C26 modified for improved corrosion resistance. 13C26 is nearly identical to AEB-L but produced by Sandvik. You can read more about the history of AEB-L, 13C26, and 14C28N in this article. read more