What is the best steel for knives? That is an impossible question to answer. A knife can serve many purposes, and only the owner can decide if the metal used is correct for his or her circumstances. Do you want a blade that holds a sharp edge? How about one with a high resistance to corrosion? What about a blade so strong it can be used for prying?
There are literally dozens, if not hundreds, of steel alloys that have been used for making knives. The precise alloy used by a manufacturer will reflect their intention for that knife’s purpose. A survival knife (like these examples), will not typically use the same kind of steel that a purpose-built tactical fighting knife will.
Therefore, the purpose of the knife will dictate what steel is the best for any particular design.
When choosing an alloy, a knife maker will often consider the following properties of the steel:
- ability to take an edge
- ability to hold an edge
- corrosion resistance
The ability to take an edge is what many people consider to be a defining aspect of how sharp a knife can be. However, the blade construction as well as the angle of the blade grind also impact the perceived sharpness of a knife.
The ability to hold an edge tells one how long a knife can be used before being sharpened again. All knives dull with use. However, some will dull more rapidly than others. Often a knife that is more difficult to sharpen will hold an edge longer.
Toughness of a steel describes the metal’s ability to resist chipping and cracking from impacts. Strength, on the other hand, describes the resilience of a metal not to be permanently deformed when cutting hard objects.
While not absolute, toughness and strength tend to be inversely proportional. In other words, the stronger the steel, the more likely it will be to crack or chip. Likewise, a very tough steel will not be very strong. This correlation is not completely true in all cases, but it is a good rule of thumb.
Corrosion resistance is simply the metal’s ability to resist stains and rust.
In addition to the metals themselves, knife makers can apply treatments to improve some aspect of the metal’s performance. For example, an oxidation finish could be applied to the surface of a knife to increase resistance to corrosion.
Most popular knife manufacturers are using several types of steels in their production. Most of those steels fall into three classes of steel: tool steel, stainless steel or carbon steel. There are many other kids of steel, but they are used less frequently for blades.
Tool steel is a general steel product that ranges in quality from average to very good. While not as popular as stainless steel, tool steel is used in quite a few knife blades.
Stainless steel is probably the most popular kind of steel used in modern knife manufacturing. It will have a chromium content of at least 13%, which gives it a high degree of corrosion resistance. Stainless steel will rust and discolor if left in a harsh environment long enough. With normal care, the steel should not corrode.
Many different stainless steel alloys exist including the popular 420, 440, AUS-6, AUS-8, ATS-34 and others.
Carbon steel blades are popular with many people who need a durable knife. They are easy to sharpen and are very tough. Carbon steel was very popular in the production of knives in years past. However, carbon steel lacks corrosion resistance.
So, if you are still wondering what is the best steel for knives, the answer is “it depends.” It all depends on what performance you are looking for from your blade. Carefully examine the reviews on the knife you are considering purchasing and decide if that steel will meet your demands.