Knife Steel – The Basics

It can be difficult to choose the best chef knife. At first it may seem like a simple case of what’s the sharpest, coolest looking knife. But how well does the knife take an edge? How long does that knife keep that edge?

Two knives with the exact same size and shape can be hugely different based on the type of steel used to make them. And there are hundreds of different kinds of steel. Many are designated by a series of numbers and letters, others are given a brand name.

Not all steels are suitable for use in kitchen knives, though. Each mixture of metals – an alloy – has its own characteristics. Such characteristics might include hardness, flexibility or grain (ability to take an edge). Though many different alloys – both patented and not patented – can be used, there are three main groups of steels that are used to make chef knives.

1) High-Carbon Steel – High-carbon steel is the classic choice of chef knives, especially vintage cutlery. It’s strong, takes a sharp edge, and stays sharp. Many professional chefs prefer high carbon steel, especially chefs that learned very traditional European cooking.

The steel is prone to rusting and discoloring, though. Acidic foods like citrus or tomatoes accelerate the process.  The knife needs a lot of maintenance to stay clean, so it’s not a good choice for anyone not willing to take the time to really care for the blade.

2) Stainless Steel – Despite the name, this steel isn’t 100% stainless. If left wet or not properly stored, it will still rust. However, it does resist rusting and discoloring very well, and it’s easy to maintain. This is the standard for inexpensive kitchen knives.

Stainless steel doesn’t take a cutting edge as well as high-carbon steel, though. It also dulls more quickly. To maintain their optimal sharpness, these knives do require very regular honing and sharpening.

3) High-Carbon Stainless Steel – The best of both worlds, high-carbon stainless steel has the edge of high-carbon steel with the stain resistance of stainless steel. Most premium chef’s knives now use this kind of steel.

The only down side of this I’d of steel is its cost. Knives made of this material do tend it be more expensive, though durable and long-lasting.

Steel Additives

Steel is an alloy, which means its a mix of various metals and other materials. The exact additives and their percentages are what make each individual type of steel. The following are some common additives that you may see listed as a knife’s features.

Carbon – All steel has some carbon in it. Up to a certain point, it adds hardness and strength to the steel. Too much carbon, however, and the metal becomes brittle.

Chromium – Chromium is the additive that produces stainless steel. “High chromium” is just another way of saying “stainless.”

Manganese – This element is found in a lot of kitchen knives. At low concentrations it improves the grain of the knife (which allows sharper edges) and helps the steel harden when it cools after production. At higher concentrations, manganese makes steel harder but more brittle.

Molybdenum – This is a hardening agent that allows a steel to harden properly when it cools. It also improves the steel’s resistance to rusting and staining.

Tungsten – This metal is also a hardening and grain-improving additive. It improves wear resistance, which can contribute to an edge’s longevity.

Vanadium – A common grain-improving additive, high vanadium blades can be sharpened to a very fine edge.

Tempering Steel

The outer layer of steel changes color during the tempering process, a chemical reaction due to the heat.

All the additives in the world can’t help a knife that hasn’t been properly tempered. Generally speaking, tempering is reheating steel after it has been rapidly cooled. The process makes e steel harder and stronger. All high quality knives will make reference to some kind of tempering method, if only to say that they have one.

A knife bade is only as good as its steel. It affects the shape the blade can take and its ability to maintain that shape. The knife’s sharpness can be affected by minute traces of other materials, as can that edge’s durability. Though it may seem to be a trifling detail, steel can make or break a knife – quite literally!

Leave a Reply