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

Edge Retention

CATRA Tests of M390 Knives

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CATRA Testing of M390 Knives

Recently two sets of CATRA studies of M390 knives have been reported. One was conducted by Mike Latham of CollectorKnives, and the other by a group of people including Clint of the Alchemy_1 Youtube channel. These reports are the product of a minor controversy over the Rockwell hardness of production knives and the relation between Rockwell hardness and edge retention. Here are links to both reports: 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

Hardenability, History - Articles - Books

O1 Steel – History, Properties, and How to Heat Treat

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O1 Steel History

O1 steel was developed in 1905 by Halcomb steel which was acquired by Crucible Steel a few years later [1][2]. However, the history is a bit more interesting than that. In 1876 a large Sheffield steel company, Sanderson Brothers, purchased Sweet’s Manufacturing Company’s Geddes Steel Works in Syracuse New York. American tariffs had led to a large reduction in exported steel from Sheffield, and steel output from the USA had also greatly increased to match. So several English steel companies setup production facilities in the US, including Sanderson Brothers. Sanderson Brothers was a very old Sheffield steel company, founded in 1776. Tool Steel development began to explode starting in about 1900 due to the recent discovery of “high speed steel” which you can read about here: The History of the First Tool Steel. The year 1900 was doubly significant because in that year there was a major consolidation of 13 of the major steel plants which used “crucible” steel production methods, accounting for 95% of the crucible steel production in the United States. read more

Damascus, Powder Metallurgy

The History of Powder Metals in Damascus Steel

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Gratitude

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I interviewed several knifemakers for this article. Thanks to Ed Schempp, Hank Knickmeyer, Steve Schwarzer, Rick Dunkerley, Jim Batson, Shane Taylor, Jeff Carlisle, Kelly Cupples, Daryl Meier, John Davis, Matt Diskin, Wade Colter, Barry Gallagher, Howard Clark, Bob Kramer, and Devin Thomas for talking to me. read more

History - Articles - Books, Toughness

How to Heat Treat 26C3 Steel

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26C3 Steel

26C3 steel is produced by Uddeholmstrip (part of Voestalpine Precision Strip) as a razor and scalpel steel. This steel is also known as 1.2002 using the German designation. I don’t know much about the history of the steel but the marketing literature says, “voestalpine Precision Strip AB has long experience and were the pioneers of both the high carbon (UHB 26C3) and the martensitic stainless steel (UHB AEB-L) razor strip grades” [1]. In the 1927 patent for AEB-H [2], reference is made to “the purest Swedish carbon steel with ‘1.05% C and 0.4% Mn'” and in a 1970 patent for a razor blade steel there is a reference to UHB 26C (the 3 is not on the end) which has the same approximate composition as the current 26C3 [3]. So I think there was probably some evolution of the composition despite the claims of the marketing material. The composition of 26C3 is shown below: read more