A knife steel is a tool that can be used to sharpen knives. It can also be used to keep blade edges straight and realigned after use.
It can be used to sharpen a knife that has become blunt due to repeated use or a blunting agent. It can be used to keep a sharp edge on your knife longer and help it perform better.
Hardness
Hardness is a measure of the resistance of a material to deformation. This property is determined by the atomic microstructure of the metal, which is the arrangement of atoms in a crystal lattice.
A steel’s hardness is measured by the Rockwell C test, which uses a combination of testing forces and types of indentation. The scale uses the letters of the alphabet to rate materials and is standardized, fast, and reliable.
When used for knives, hardness is important because it allows the blade to resist plastic deformation during use. This is especially true for the edge.
Hardness is also an indicator of corrosion resistance, as steels with more than 12% chromium are less likely to rust over time. This is important for knives that are frequently exposed to salt water or other harsh environments.
Toughness
Toughness is a measure of how resistant a steel can be to both high stress and high strain. It is a property that can mean the difference between life and death in a survival situation when a knife breaks, so it’s important to have a blade with a good level of toughness.
Toughness also translates into how likely the blade is to rust over time. All stainless steels are susceptible to rusting under certain circumstances but those that are alloyed with chromium tend to be better at resisting corrosion over a long period of time.
The hardness of a knife steel is measured on the Rockwell C scale (HRC). As a general rule, harder steels are less brittle but more difficult to sharpen and break easily. The hardness of a knife is not necessarily the only factor that will affect its performance though, as heat treatment and edge geometry will play a large part as well.
Corrosion Resistance
When you use a knife, you need to know that it can handle the environment and keep up with your needs. That means that the blade has to be durable enough to resist water, damp environments, and salt.
Toughness and corrosion resistance are two of the most important properties that you need to consider when selecting a knife steel. Corrosion resistance is what keeps the blade from dissolving in water or other liquids like sand and salt.
The best knife steels will balance hardness, toughness, wear resistance, and corrosion resistance to ensure that they are the most effective at what you need them for. Some knife makers have created unique alloys that achieve the best of all worlds.
Edge Retention
When a knife steel is used for cutting, edge retention is a key factor. It can determine whether a blade will cut cleanly, or if it will eventually become blunt and need to be sharpened.
Edge retention is a balancing act of four main properties: hardness, toughness, corrosion resistance and ease of sharpening. The best steels have a balance of all four, but the balancing act changes depending on the knife’s intended use.
In general, a steel that’s made harder (high carbon and carbides) will be more abrasion resistant, but it can also be brittle and difficult to sharpen. This is a tradeoff in qualities that is very common with many of the knife steels on the market.