August 1, 2018 by SteelWolfKnives
What Steel Should I Use?
There are many different kinds of steel, each of which have their own advantages and disadvantages. The main categories used (at least in knife work) are mild steel, high carbon steel, and stainless steel. Mild steel is used for decoration and testing ideas. High carbon steel is used for blades, and stainless steel is used for weather resistant items.
Mild steel is the most basic and cheapest form of steel available. It is great for testing things that could otherwise ruin more valuable pieces. It is also great for learning new skills, such as welding or metal engraving. If you are doing blacksmithing with your pieces, it is a great learning tool because it acts very similarly to high carbon steel (the material that most bladesmiths use for handmade knives). However, it is not very good for the final product if you are making a bladed object. Mild steel lacks the carbon and the crystalline structure necessary to retain a sharp edge. You can definitely give it a sharp edge, but if you were to swing that knife into a log or 2 by 4, it would be noticeably more dull after only a few chops. So while mild steel is great for practice and learning, it is terrible for the edge of knives.
High Carbon Steel
High carbon steel is steel that has at least 0.3% carbon present in it. The presence of carbon is what allows the steel to be hardened. Not enough carbon means that the metal cannot be hardened and will fold and deform (like mild steel chopping wood). Too much carbon means that the steel will not be able to bond to itself correctly and is more likely to shatter or crumble, for lack of a better word. The amount of carbon that you want will depend on the project. Swords can use 1055 steel (steel with 0.55% carbon), which gives it a little more flex. Without it, the sword could crack over the long blade. My personal favorite to use for knives is 1095 steel (steel with 0.95% carbon in it). I find that it holds an edge very well, and is hard but not too brittle. Because of the shorter length of a knife, flex is not as big of a problem.
Stainless steel is definitely the hardest of the three types of steel to work. It hardens differently, quenches differently, and moves differently with a hammer. However, it is more resistant to weather and to wear and tear, making it a great choice of material if you plan on using it a bunch without doing much maintenance. It is less affected by water, meaning that if you forget to oil it between uses or if you leave it out of the sheath overnight, it won’t be a problem. The problem is that it is much harder to work with and requires special tools if you want to do it right. Many of the common types of stainless steel, such as 440C and 154CM, use air quenching in order to harden correctly. This is very different than water or oil quenching, which most high carbon steels use.