History - Articles - Books

How I Became a Knife Steel Metallurgist

Thanks to Jon Broida of Japanese Knife Imports and Anton Kudris for becoming Knife Steel Nerds Patreon supporters!

When I was 16 I went with my father to the Las Vegas Custom Knife show. My interest in custom knives up to that point had been pretty limited. My father, Devin, has run a Damascus steel business for as far back as my memory goes. I remember looking at the A.G. Russell catalog and seeing some of the cool knives. I remember wanting a pocket knife, but I don’t remember being any more interested in knives than I was in, say, Vans shoes. At the knife show, however, my perspective changed. There was table after table of custom knives and custom knifemakers all with different styles and stories to sell their knives. Knifemakers come in all different types from the aw-shucks cowboy to the intense self-defense salesmen. I was most interested in the knifemakers that were making claims about the superior performance of their knives. From the lockup, to edge geometry, to steel, etc. there were barkers promoting it all. I spoke to a man who claimed that he had a proprietary steel for his fillet knives that was better than any other available. He flexed the knives 90° to demonstrate the superiority of the steel. Another knifemaker boasted about his extensive heat treatment protocol that would lead to the best performing hunting knives available. read more

Edge Retention, History - Articles - Books, Steel and Knife Properties, Steels, Super Steels, Toughness

Super Steels vs Regular Knife Steels

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Super Steel

I see frequent references to “super steel” online, and I was curious about how long that terminology has been around. I did searches on bladeforums as it is one of the oldest knife forums. The number of references to “super steel” has increased over time, but so have the number of posts on bladeforums. I saw how many references to “super steel” there were in each year, and then as a proxy to how many posts there were on bladeforums I did a search for “154” and saw how many references there were each year. Google tops out at 200 results but at that point the dataset was big enough to get an idea: read more

Edge Stability

What is Edge Stability? Part 2 – The Experiments

Thanks to Gary Creely and Sans Jeux for becoming Knife Steel Nerds Patreon supporters!

Background

Read Part 1 before this article as it covers the ideas behind the Edge Stability theory and how things like hardness of steel, carbide volume, and carbide size are thought to affect knife edges. Then you will have an understanding of what we are looking for in the experiments described below. read more

Corrosion Resistance, Nitrogen-alloyed, Steels

Nitrogen-Alloyed Knife Steels

Thanks to Matthew Hoffman, Tryggvi, and Ron Dillon for becoming Knife Steel Nerds Patreon supporters!

In previous posts I have written about the process by which steel is hardened. The steel is heated to a high temperature phase called austenite, where carbides are dissolved and carbon goes into solution in the austenite. During rapid quenching the carbon is trapped between the iron atoms and a phase called martensite is formed. Martensite gains its high hardness from the distortions to the atomic structure that come from carbon in between the atoms.  read more

Steel and Knife Properties, Steels

Ranking the Steel Ranking Articles

Note: I now have a steel ratings article of my own, read it here: Knife Steels Rated by a Metallurgist

Intro

Thanks to Stacy Apelt for becoming a Knife Steel Nerds Patreon supporter! Based on a poll of Knife Steel Nerds Patreon voting members, we have decided to purchase a small impact tester for knife edges. This will allow us to study the effects of steel, heat treatment, edge geometry, sharpness, etc. on chipping and rolling of edges. read more

Edge Stability

What is Edge Stability?

Thanks to Keith Nix and Benaiah Brabant for becoming Knife Steel Nerds Patreon Supporters! The vote is still open on Patreon for what equipment will be purchased for future research. 

Edge Stability

I got help directly from Roman Landes in writing this article (Thanks Roman!). The content below is based on Roman’s book, Messerklingen und Stahl: Technologische Betrachtung von Messerschneiden (Knives and Steel: Technological Examination of Knife Edges), as well as discussions with Roman. However, since the writing is mine the ideas are naturally filtered through me. Any mistakes are my own.  read more

Sharpness

Sharpness vs Cutting Ability

Thanks to Matthew Berry for becoming a Knife Steel Nerds Patreon supporter!

CATRA, Sharpness, and Cutting Ability

I got several good comments on the article about CATRA edge retention testing regarding sharpness and cutting ability. The edges tested with more acute angles (20° edge is more acute than 50°) started out cutting better and remained that way through the standard 60 cuts. However, the measured width of the edge with the worn 20° edges was larger than with the 50°. So this leads to a question: which was sharper? And if the 50° was indeed sharper due to its narrower edge then why was it not cutting as well? read more