Niobium-Alloyed, Nitrogen-alloyed, Super Steels

CPM SPY27 Experiments – Toughness, Corrosion Resistance, and More

Larrin

Thanks to A.N. Nash, Matt Collingwood, Noah Cowan, James Pierce, and Jay Caponetti for becoming Knife Steel Nerds Patreon supporters!

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

Forging, Toughness

Ranking Toughness of Forging Knife Steels

Larrin

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Low-Alloy Steel Testing

Over the past two years or so we have tested the toughness of many knife steels using a simple charpy impact test. You can read about the specifications of the test on this page. With the samples tested in this article I got a lot of help from Warren Krywko and Devin Thomas as well as donated steel from Alpha Knife Supply, Barmond Special Steels, and Achim Wirtz. This article focuses on the toughness testing performed on “low alloy” and carbon steels that are often used by forging bladesmiths. It is possible to forge high alloy steels, of course, though it does not appear to be very common even today. read more

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

Friction Forged Knives – Diamondblade Friction Stir Processing

Larrin

Thanks to Keith Coleman, Paul Bruno, Lotiel Vardamir, and Lennart Palkovits for becoming Knife Steel Nerds Patreon supporters!

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

Heat Treating and Processing, History - Articles - Books, Steel and Knife Properties

S35VN Steel – Properties and How to Heat Treat

Larrin

Thanks to Konstantinos Noulis, Neil MacEachern, and J Kane Searcy for becoming Knife Steel Nerds Patreon supporters!

S35VN Steel History

S35VN is a steel developed and produced by Crucible Industries, released in 2009. The steel was developed by Maria Sawford as a modification of S30V by reducing the vanadium content, adding 0.5% niobium, and removing the nitrogen addition (incidental nitrogen is still present). Powder metallurgy steels typically have at least 0.03% nitrogen [1][2]. These changes led to a steel with improved toughness and machinability relative to S30V at the cost of some edge retention. Heat treatment response and corrosion resistance remained approximately the same as S30V. More information on the history leading up to S35VN can be seen in this article on the newer S45VN. read more

Corrosion Resistance, Super Steels

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

Larrin

Thanks to Aaron T Grote, J. Braun, Mr. KnifeGuy, jethro fluegel, Philip Ward, and Matt Peterson for becoming Knife Steel Nerds Patreon supporters!

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