Heat Treating and Processing, History - Articles - Books, Metallurgy Principles, Reviews

Review – Kevin Cashen’s Guide to 1080 & 1084

Thanks to Edward Braun, Mark Reich, and Alex Kaplan for becoming Knife Steel Nerds Patreon supporters!

Misc. updates: I added some toughness numbers that I had previously been unable to track down comparing 440C and 154CM to the 154CM article. I also added a summary of a very interesting new journal article about the effect of grain size on steel toughness to the Grain Refinement article.   read more

Edge Retention, Steel and Knife Properties

Maximizing Edge Retention – What CATRA Reveals about the Optimum Edge

Thanks to Ed Schempp, Matus Kalisky, and Chin Lim for becoming Knife Steel Nerds Patreon supporters! Your support allows us to fund CATRA studies. 

Cutlery and Allied Trades Research Association (CATRA) makes an edge retention tester that measures slicing of cardstock impregnated with 5% silica (sand). You can see a video of what the test looks like here: read more

Corrosion Resistance, Metallurgy Principles, Steels

How Much More Chromium Does D2 Need to be Stainless?

Thanks to Devon Craun for becoming a Knife Steel Nerds Patreon supporter! Your support is funding knife steel research. 

Some materials like aluminum form a passive oxide layer that prevents further corrosion. Steel is not one of those materials. Instead, steel forms iron oxide, or rust, that doesn’t protect the underlying iron and flakes off leading to further corrosion. However, when sufficient chromium is added then a chromium oxide passive layer forms which protects the steel from corrosion in a similar way to a metal like aluminum with its own aluminum oxide layer. A simple schematic diagram shows the passive film vs rust [1]: read more

Heat Treating and Processing, Steels, Tempering, Toughness

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

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