- 1). Select your tool steel. This step depends entirely upon the material you are turning in the lathe and the lathe itself. For wood turning, a good stock of carbon steel or stainless steel can be sufficient, with a length of anywhere from 3 to 6 inches for small bench top wood lathe to upwards of a foot for a floor model. The thickness of the material depends completely on the style of cut you will end up making.
For metal turning, you will typically buy a harder grade of tool steel, such as high speed steel. For harder materials such as stainless steel and other carbon steels, tungsten carbide tool bits are also used, but provide greater risk to the home toolmaker. The size of a tool steel bit again depends on the size of the lathe, but typically it will be 2 to 4 inches in length and anywhere from an eighth of an inch to an inch in thickness. - 2
Common lathe tool shapes for wood (top) and metal (bottom)
Determine the cutting edge geometry. Depending upon the type of cut you wish to make, there are a number of styles of cutting edges you can put on a tool. These figures represent a small selection of the many styles of cutting edge. - 3). Grind the rough shape. Using the bench grinder, grind the rough shape into the tool steel, making sure to constantly use the container of water to cool the metal bit to prevent overheating and loss of temper. As one approaches the final shape of the tool bit, it is important to try and maintain the grinders' cutting action perpendicular to the cutting edge.
- 4). Finish the edge. Once the final shape is reached with the bench grinder, use successively finer honing stones to bring the edge into its final, sharpened state. Caution here is advised as the tool will be quite sharp. As with the prior step, be sure to use a motion of the tool bit upon the honing stone that is perpendicular to the cutting edge.
- 5). Harden and temper the tool if necessary. If the tool steel overheated, or if it was not in its final hardened state before grinding, it will need to be hardened to provide the best cutting action. Different procedures are needed for different steels, so one will need to consult the manufacturers recommendations for hardening the tool steel. But the process likely will involve heating the steel until glowing hot, quenching it in water or oil to cool it rapidly, and then heating the tool again to a much lower temperature in order to prevent brittleness.
- 6). Attach a handle for wood turning tools. If the completed tool is for turning wood, they usually employ a handle with which to use the tool. There are many styles of handle one can employ, the only real criteria is that it should securely hold the tool steel and provide a strong grip on the tool for the lathe operator.
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