The world of steel is as fluid as molten metal. It is ever-evolving. Steel as a matter of opinion is very subjective as it relates to knives and knife aficionados. There is no clear cut answer as to which is the best steel. There are different requirements and preferences. Steel is alloyed with various other elements that combine to produce special properties. Once a particular alloy combination (or steel type) is selected, specific procedures are used to maximize the unique qualities required for that steel to perform. There is an old proverb, “There was never a good knife made of bad steel.” This statement, just like steel itself, is completely subjective as it relates to knives and the user. As Sal Glesser of Spyderco says, “No best, all good, just different”.
This information will provide you with a foundation to make your own determinations where steel is concerned and perhaps assist you in better defining what your own preferences are and why. A word of caution, this information is not intended to be all inclusive, nor could it ever be.
There are over 3000 different types of steel, each having its own positive and negative attributes. In order to determine your own preferences, it is perhaps best to first understand the history of steel and how it is made.
Although an exact date of discovery is not known, man has been forging steel for as long as he’s been working iron. When iron is heated in a fire it naturally absorbs carbon from the fuel source. Early ironworkers learned to make steel by heating wrought iron and charcoal (a source of carbon) in clay boxes for a period of several days. By this process the iron absorbed enough carbon to become a true steel. Iron by itself is a relatively soft metal, it does not hold a good edge. However, if you add carbon it hardens the iron, making steel. Steel has proven to be ideal for making edged weapons.
At a very simplified level, making steel is like baking a cake. You follow a precise recipe to achieve the type of cake (steel) that you desire. You begin with flour (iron) and from there you add various ingredients (elements). These additional ingredients will determine what type of cake (steel) you end up with. Once you have added all of the additional ingredients (elements) you are left with a batter that is ready to bake (heat treat). Baking (heat treating) is just as much a part of the “recipe” as the ingredients (elements). If not done properly, several properties can suffer. Once baked, you have a new – completely different – finished product. Your cake will forever be a cake, it can never go back to being batter. Of course steel can be re-melted to a molten state, but that simply is the beginning of becoming a new type of steel. Steels are classified accordingly with the elements used in production. These classifications are, Carbon Steels, Alloy Steels, Stainless Steels, and Tool Steel. All steel is composed of iron and carbon. It is the amount of carbon, and the additional alloys that determine the properties of each grade. (See: Part 2, Steel Making and our Steel Glossary)