Austenitizing, Quenching, Tempering, Toughness

How to Heat Treat 8670

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

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

Carbides, Corrosion Resistance, Niobium-Alloyed, Nitrogen-alloyed, Powder Metallurgy, Steel and Knife Properties, Super Steels

What is the Future of Stainless Knife Steel Design?

Thanks to Aram Compeau, Gordon Olafson, and John Walton for becoming Knife Steel Nerds Patreon supporters! I have an update on Patreon about the “rare earth” elements in AR-RPM9 steel.

I completed a minor revision to my new book Knife Engineering to correct a few typos. Some readers outside the USA also asked for more conversions from Fahrenheit than were present originally, so I incorporated both Celsius and Fahrenheit everywhere in the book in the text and tables, though some images and charts still have only one temperature scale or the other.  I wouldn’t say that the changes in the revision are big enough to buy a new one if you have it already, this is not a new edition, but if you haven’t purchased one yet this is as good a time as any. read more

Heat Treating and Processing, Steel and Knife Properties

13 Myths about Heat Treating Knives

Thanks to Lee Rothleutner and J Hamm for becoming Knife Steel Nerds Patreon supporters!

General Heat Treating Myths

1. Heat Treating is the most important factor for high performance knives. This one started out along the lines of “even the best steel will perform poorly if given a bad heat treatment,” and that I can’t disagree with too much. However, it has become somewhat fashionable to talk about knife performance as entirely (or almost entirely) controlled by the knifemaker’s skill in heat treatment. This has some truth to it as knifemakers who use a subpar heat treatment will certainly have subpar performance. However, the heat treatment can only do so much. No heat treatment is capable of making high carbide CPM 15V into a high toughness steel. No heat treatment can turn 1095 carbon steel into a stainless. And I would argue that the single most important factor for knife performance is the edge geometry rather than the steel selection or heat treatment. The edge geometry greatly controls the cutting ability and edge retention of the knife and also resistance to chipping and rolling. The image below shows measured edge retention of 154CM knives with different edge angles so you can see the vast difference in measured performance (higher number means more cardstock cut). Of course, focusing on any one of these factors at the expense of the others: steel selection, heat treatment, and edge geometry, is a mistake and each should be optimized for the given knife. But if we were to pick one factor that is the “most important” I’m not sure that heat treatment would be the one. read more

Forging, Toughness

Toughness Improvement of High Carbon Tungsten Steel 1.2562

Thanks to all the new Knife Steel Nerds Patreon supporters that have joined since our big article on CATRA testing. The response has been phenomenal. We only need 4 more supporters to reach 200! Brandon Percival, Jason Stone, Fixall, John Schmidt, Adam Ringgenberg, Adam Webb, Shah Paul, Andy, Chad Shoopman, Dylan Giagni, Adam Nolte, John Scarborough, Datafox, Ben Secrist, Noah, Josh – REK, Robert Towe, NJO, Dd, Andrew Bounds, Nathan Gee, and hsc3. read more