The home knifemaker is very fortunate in having a wide range of steels available for his craft. Many can be obtained at very low cost, while some can be got just for the asking. However, before we decide upon a source of supply, we should take a brief look at the composition of steel.
In simple terms, steel is a mixture of iron and carbon. To this may be added various trace elements such as chrome, vanadium, manganese etc. In the first instance we have carbon steels, in the second we have alloy steels. Carbon steels may also contain alloy elements.
Carbon steels are the most widely used, and thus are the easiest to obtain. The percentage of carbon present in the steel will determine the hardness of the steel and its potential use.
Steel with a content of about 0.2% is known as low carbon steel. It is not hardenable, and thus is of little use to knifemakers. Mild steel is another name for low carbon steel, and it is widely used in such diverse fields as buildings, car bodies etc.
Steel with a carbon content of between 0.2% and 0.6% is a medium carbon steel. It is a hardenable steel and is widely used in the manufacture of tools, some bolts and fastening devices and other requirements where greater strength is required.
High carbon steels have a carbon content of around 0.7% to 1%. These are steels used for metal cutting tools such as drill, files etc.
Given a choice we suggest that you select a medium carbon steel. While it cannot be hardened to such a high degree, it usually makes a better knife than high carbon steels. Also there is less tendency for the finished edge to chip, or the blade to break if dropped.
The traditional choice of home knife makers has always been a worn out file. While they can make a good knife, we do not recommend using files. It is too easy to overharden the steel again, which can lead to breakages.
A second traditional source of material is old car springs. We tend to favour springs, as they are often given away by wreckers. The also contain sufficient steel to make a number of knives. Car springs a re best used with a forge, as some shaping and thinning can be done on the forge.
Industrial hacksaw blades are sometimes used. Many of these fall into the ‘high carbon’ class, so are not suitable. However the steel is about the right size and thickness, so may be worth considering. Large machine shops, engineering works, steel plants etc. throw away hundreds of blades per year. Often they will give you old blades just for the asking.
Another good source of supply is from old circular saw blades. These are the right thickness, and will turn into a number of knives. Unfortunately they are not so easy to obtain. Try the timber yards. Also, keep your eyes open around second hand shops and flea markets. They sometimes turn up at reasonable prices.
In the same category are larger hand saws. Old ‘two-man’ cross-cut saws can sometimes be purchased cheap around the second hand shops. Again, the blade is around the right thickness.
