Getting Started

I have articles categorized so you can see which look the most interesting to you without going through every page of the blog. 

Steel and Knife Properties

Strength and Hardness of Steel

“Flexing,” as opposed to bending and it staying bent, is controlled by a non-intuitive set of properties: Why Doesn’t Heat Treating Affect Steel “Flex”?

How Does quenching steel make it hard? What does carbon do to make it hard? What Makes Quenched Steel so Hard?

How is strength measured anyway? What steel are they comparing to when they say spider silk is stronger? Is Spider Silk Stronger than Steel?

Does hardness correlate with strength? Does Rockwell hardness predict toughness and wear resistance? Rockwell Hardness is the Megapixels of Knife Steel Specs

Toughness

Read about what makes some steels tougher than others, and How Chipping of Edges Happens at a Microscopic Level

There have been a variety of toughness testing methods used on knives themselves as opposed to measuring steel properties. Here is a summary of the published studies: Tests of Knife Edge Toughness

Grain refinement has been promoted by many knifemakers as a way to achieve super steel properties. I describe the process in Austenitizing Part 3 (see under the Heat Treatment category). This article is all about how grain refinement changes properties: How Does Grain Refinement Lead to Improved Properties?

At cold temperatures steel  has lower toughness. There are steels to select and heat treatments to perform to maximize low temperature toughness, however. Learn Why Cold Steel is Brittle.

Corrosion Resistance

How Heat treatment and carbon-chromium balance affects corrosion resistance, why D2 isn’t stainless, and How Much More Chromium Does D2 Need to be Stainless? 

I ranked steels in terms of corrosion resistance after describing the methodology for doing so in Which Knife Steels Have the Best Corrosion Resistance?

I did a sharpness study with three knives using steel with different levels of corrosion resistance to learn if Acidic Food Affects Edge Retention.

Edge Retention

CATRA testing of 154CM, CPM-154, Effect of cryo, edge angle, sharpening, and thickness behind the edge on edge retention: Maximizing Edge Retention – What CATRA Reveals about the Optimum Edge

A major knife company sent me a massive dataset of CATRA tests and I analyzed the steel factors that affect slicing edge retention like hardness, carbide type, and carbide volume in Which Steel Has the Best Edge Retention? Part 1. I then analyzed the edge wear behavior itself and answered questions like which steels lose their initial sharpness the fastest in the Part 2 article

I compared the predictions of CATRA generated in the articles above and compared them with published rope cutting experiments to determine if CATRA is a good prediction of “real” knife performance in Can CATRA Predict Rope Cutting Performance? 

Edge Stability

Edge stability is a bit difficult to understand without a good background about what it is. Essentially it is a combination of both strength and toughness for avoiding both rolling and chipping. What properties provide better edge stability? Which steels are more stable?

What is Edge Stability? Part 1

What is Edge Stability? Part 2

Sharpness and Cutting Ability

Cutting ability and sharpness are not the same thing. Edge geometry matters independent of sharpness for cutting. Also I define what sharpness is, because I bet you don’t know: Sharpness vs Cutting Ability

Rating Steel Properties

There are a lot of articles out there with ratings and rankings for the various knife steels to know which is better than which. Do they know what they are talking about? Or are they using random number generators and fancy bar charts? Find out in Ranking the Steel Ranking Articles

What is a super steel? Why are they super? Are they actually super? How many times can I write the word super? Super? Super Steels vs Regular Knife Steels

Knife Making

Is sharpening with a grinder bad? Should you use stones instead?

Heat Treatment and Processing of Steel

Forging

Cold Forging or Cold Rolling is sometimes performed on steel after annealing and before austenitizing/hardening. Read more in Cold Forging of Steel

Austenitizing 

Heating to high temperature prior to quenching to harden steel. Read all about it in:

Learn what is going on in the steel when you heat it up to high temperatureAustenitizing Part 1 – What it is

Should you austenitize at a higher temperature or a lower temperature? Temper lower or higher? Austenitizing Part 2 – Effects of Properties

What is the difference between preheating and prequenching? Which “pre” treatment should you use? Does a triple quench work? Austentizing Part 3 – Multi-Step Austenitizing

Can you trust your magnet during heat treating?

Quenching of Steel 

What happens in the microstructure during quenching and what martensite is: What Makes Quenched Steel so Hard?

How fast do you have to quench? Hardenability of steel

Cryogenic Processing of Steel

How cold temperatures lead to the transformation of retained austenite to martensite and how to maximize hardness with cryo in Cryo Part 1

How cryo affects toughness and strength in Cryo Part 2.

How cryo affects wear resistance in Cryo Part 3. It’s complicated.

Tempering

All of the changes that happen in steel during tempering. What are you trying to accomplish during tempering? What Happens During Tempering of Steel?

What is Tempered Martensite Embrittlement? Why shouldn’t you temper between 500 and 700°F? Silicon Additions for Improving Steel Toughness

Austempering and Bainite

Learn about austempering, what bainite is, and whether bainite leads to higher toughness than martensite: Bainite vs Martensite – The Secret to Ultimate Toughness? 

Steel History and Design

Damascus Steel has been around for centuries, and there are a lot of myths all about it. There are two types called pattern-welded and wootz. Find answers to questions like whether damascus cuts longer than “normal” steels: Five Myths About Damascus Steel

Tool steel was invented in the 1860’s, but really took off from some incredible developments in the 1890’s and early 1900’s: The History of the First Tool Steel

Stainless Steel was invented pretty shortly after the explosion of new tool steels and high speed steels in the early 1900’s. There were several people working on stainless steel in the same time period, but the man who first produced it commercially was particularly interesting, because The First Stainless Steel was for Knives

Tool Steel and High speed steel development continued through the transition from tungsten to molybdenum and large additions of vanadium. And James P. Gill, an amazing metallurgist, wrote amazing books about steel metallurgy that hold up today: The Development of High Vanadium Steels, M4, and the First Tool Steels Book

How 154CM was developed, why there is so much molybdenum in it, and how it took over 440C’s crown as the top stainless steel: 154CM- Development, Properties, Use in Knives, and Legacy

Want to know how powder metallurgy works? How is it made? How does it improve steel? Are there videos? Yes, yes there are: What is Powder Metallurgy? 

I wrote about the history of carbon and stainless steel in knives. Who used stainless steel first? Why did stainless steel have a poor reputation? I interviewed several interesting people including the late, great A.G. Russell (RIP) to understand the history of custom knives: Carbon vs Stainless Steel in Knives

D2 has been around for a long time. Where did it come from? Why was it used in knives? Does it hold up against newer steels? All About D2 – Development, Use in Knives, and Properties

Before its bankruptcy, Crucible metallurgists made an improved version of 3V that has never been offered for sale: 3V Modified – The Lost Crucible Steel

Nitrogen-alloyed steels like Vanax and LC200N are the new hotness. How do they get nitrogen into the steel? Why add nitrogen at all? Nitrogen-Alloyed Knife Steels

All about tungsten alloyed steels like the Blue Series, 1.2562, 1.2442, 1.2519, O7, V-Toku series, etc: Is Blue Super Steel Actually Super? 

All about what cobalt does to steel and whether N690 and VG-10 have similar properties: Why There is Cobalt in VG-10

Does Silicon improve steel properties? What makes shock resisting steels so tough? Silicon Additions for Improving Steel Toughness

Analysis of the new Damasteel products N11X and Damacore DC18N. What is it? Do you want it? New Steel Analysis – Damasteel N11X and Damacore DC18N

History and Properties of 52100 Steel – What 52100 was developed for and when, why knifemakers started to use it, and what the chromium does to change its properties relative to 1095.

Niobium-alloyed knife steels – What niobium does to steel and how it can lead to very good combinations of properties that the steel companies have not yet fully taken advantage of. Discussion of steels like S35VN, S110V, Niolox, and others.

All About AEB-L – Properties, history, development, best uses, and more about AEB-L. The most complete collection of information on AEB-L.

Testing of Specific Steels

Micrographs of Niolox, CPM-154, and AEB-L

Does forging temperature affect toughness? What about a triple quench? What tempering temperature should you use? Cru Forge V – Toughness testing, Process, and Background

This article covers a lot of heat treatment parameters for Z-wear to find the optimal heat treatment: Toughness Testing – Cru-Wear, Z-Wear, Upper vs Lower temper, Cryo vs No Cryo

How to heat treat 5160 for optimal toughness. It has a surprisingly narrow range of optimal temperatures

I wrote about what limits hardness in stainless steels, using Vanax as an example.

Steel Alternatives

There is an interesting Youtube channel where a guy makes knives out of weird materials like chocolate, wood, Jello, and conch shells. What can we learn about knife materials from his videos? The Sharpest Youtube Channel in the World

Quizzes

Are You a Steel Nerd?

Results and analysis of Steel Nerd quiz

Reviews

Kevin Cashen made a DVD where he introduced heat treatment to novices focusing specifically on 1080 and 1084: Read Review – Kevin Cashen’s Guide to 1080 & 1084

A list of recommended books on knife design and metallurgy to get you started. One of them is free! Book Recommendations for the Knife Steel Nerd

Book Review – Damascus Steel Swords: Solving the Mystery of How to Make Them

Interviews

Phil Wilson is an awesome knifemaker who is very thoughtful about how he approaches knife design: Interview with Knifemaker Phil Wilson about Performance Blades and His Journey with Knives

I interviewed Zvi who started the website Zknives.com which has a lot of awesome articles and of course the mega-sized knife steel composition database.