Thanks to AJ, Tobias Hangler, Benjamin Whitaker, Mike Latahm, Mike Pini, Jonathon Pye, Allan Benjamin, and Zaur for becoming Knife Steel Nerds Patreon supporters!
My new book Knife Engineering is now in stock at BladeHQ.
Thanks to Dinkma, Gavel John, and Roger Rozenberg for becoming Knife Steel Nerds Patreon supporters!
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.
10/15/2020: I added M398, WFN, Nitrobe 77, and Vancron
2/24/2020: I added 420HC, CPM-T15, Rex 76, S125V, SPY27, and Z-Max/Rex 86
2/10/2020: I added 26C3, 1.2442, 1.2519, 1.2562, Blue Super, V-Toku 2, and A8 Mod.
Thanks to Richard Patterson, Patrick Guignot, Aaron Lee, and David Richardson for becoming Knife Steel Nerds Patreon supporters!
Hardenability
How fast one must quench steel is controlled by its hardenability. Hardenability is not a measure of how hard a steel can get. Instead it is a measure of how fast you have to quench to achieve max hardness for a given composition. Therefore a steel with 0.2% carbon can have high hardenability without being able to reach a particularly high hardness; the steel can be allowed to cool in air and achieve more or less the same hardness as when it is quenched in water. On the other hand, a steel with very high carbon content that can reach very high hardness can have low hardenability, requiring a water quench to achieve its potential hardness.
The easiest way to learn about knives and steel is probably through my book: Knife Engineering; Steel, Heat Treating, and Geometry. However, all is not lost if you want to start on the website. Look at the following articles first to get started.
