Category: Tempering

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Austenitizing, Cryo, Edge Retention, Edge Stability, Hardness, Heat Treating and Processing, Tempering, Toughness

What is the Best Hardness for MagnaCut Knives?

Larrin

Thanks to the new members of our Knife Steel Nerds Patreon community:

Chris Hancock, Chad Morris, Edward Voss, Liam Gogley, Erik Turner, Nathan Raptis, Nick Dunham, Joe Busic, Will Red Five Forge, Dmitry Kiyatkin, Edward Edmonds, Asinelli, Mattew Reagan, Nate, Dan Barrett, Malachi Chou-Green, Nats Spawnee, McKenzie Kelsay, Jantz Supply, Adam Webb, Brian Baley, Blade HQ, and Mark Demshock. read more

Austenitizing, Quenching, Tempering, Toughness

How to Heat Treat 8670

Larrin

Thanks to George Walton, Josh Perdue, Bill Fitzgerald, and Donovan Phillips for becoming Knife Steel Nerds Patreon supporters!

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. read more

Annealing, Austenitizing, Forging, Heat Treating and Processing, Quenching, Tempering

How to Use a Steel Datasheet to Develop a Heat Treatment

Larrin

Thanks to David Reem, Colton, camilo, Brendan Gildea, Vince Koacz, Monery Custom Cutlery, Curt E, Shannon Sanders, Brazilian Blades, Rory Kelly, Brunhard, Zachary Chumley, Noel, Adam Nolte, Gundam lupus, and Jan Huch for becoming Knife Steel Nerds Patreon supporters! I still don’t know when it will be time for the announcement of my new steel so until then you can get all of the data on its properties exclusively on Patreon. read more

Austenitizing, Edge Retention, History - Articles - Books, Steels, Tempering, Toughness

A2 Steel – History and Properties

Larrin

Thanks to Dan Pierson, Steve R. Godfrey, Bryan Fry, and Timothy Becker for becoming Knife Steel Nerds Patreon supporters!

History

A2 steel is quite old, though determining the exact year it was released is a bit difficult. A2 steel was developed in the early 20th century during the explosion of tool steels that occurred after the discovery of high speed steel which was first presented in 1900. You can read about that history in this article: The History of the First Tool Steel. During the development of the first high speed steel included the switch from manganese to chromium as the primary hardenability element, and most high speed steels had about 4% Cr. That high chromium content was primarily for “hardenability” which is the degree of cooling required to achieve full hardness. A “water quenching” steel has low hardenability and must be quenched very rapidly from high temperature, and an “air hardening” steel can be left in air and it will fully harden. You can read more about hardenability in this article on quenching. The first high speed steel came to be known as T1, which had 4% Cr and 18% W (tungsten). The earliest record I have found of a precursor A2-type steel is in a summary of tool steels in 1925 [1], while summaries of tool steels from 1910 [2] and 1915 [3] do not have any similar steels. Therefore these types of steels probably arose sometime between 1915 and 1925. read more

Austenitizing, Cryo, Hardness, Heat Treating and Processing, Nitrogen-alloyed, Tempering

Heat Treating Vanax – How Hard Does it Get?

Larrin

Thanks to David Suitor, Drakopoulos Stelios, and Maxim Bellehumeur for becoming Knife Steel Nerds Patreon supporters!

Vanax

Vanax is an interesting steel because of its good combination of toughness, wear resistance, and corrosion resistance. I wrote about Vanax along with other nitrogen-alloyed steels in this article, to describe how the steel is designed. While the datasheet shows it being capable of 59-61 Rc, I was curious about how hard the steel can go. The steel may be good for kitchen knives, for example, where very thin edges and high hardness is common. And kitchen knife users may appreciate the excellent corrosion resistance of Vanax in the presence of water, salt, and acidic foods. read more

Cryo, Tempering, Toughness

Cryogenic Processing of Steel Part 2 – Toughness and Strength

Larrin

Thanks to Gator, Russell Dodd, and Matt de Clercq for becoming Knife Steel Nerds Patreon supporters!

Introduction

Part 1 of the Cryogenic Processing series covered the transformation of retained austenite to martensite and the increase in hardness that occurs. That is the least controversial aspect of cryogenic processing of steel. The other two primary properties of steel affected by cryo processing are toughness and wear resistance. Both of these properties can be difficult to pin down as they have high variability. Tool steels are known for their relatively poor toughness which means we are often comparing small numbers. read more

Silicon-Alloyed, Tempering

Silicon Additions for Improving Steel Toughness

Larrin

Thanks to Colin Shannon and Robert Williams for becoming Knife Steel Nerds Patreon supporters!

High Toughness Steels

There are a series of shock resisting steel designed for high toughness (see this article to learn about toughness). A popular one is S7, an air hardening steel that can reach relatively high hardness. Another steel in the “S” series, S5, is reported to be even tougher [1][2][3][4]: read more

Heat Treating and Processing, Steels, Tempering, Toughness

Toughness testing – Cru-Wear, Z-Wear, Upper vs Lower temper, Cryo vs No Cryo

Larrin

Thanks to Paul Hart and James Covington for becoming Knife Steel Nerds Patreon supporters!

I recently completed some toughness tests on samples that were heat treated by knifemaker Warren Krywko. The steel was donated by Chuck Bybee of Alpha Knife Supply. The samples are subsize unnotched charpy specimens with dimensions as specified on the bottom of this page: http://knifesteelnerds.com/how-you-can-help/ If we can get more people to make toughness specimens we can have more comparisons between steels, hardness points, heat treatment parameters, etc. Patreon dollars are for the purpose of paying for machining, shipping, testing, etc. for tests like toughness and CATRA edge retention, so if you are able to contribute that way please visit the Knife Steel Nerds Patreon page.  read more