Features: These center drills are used in metalworking to provide a starting hole for a larger drill. They can also be used to make a conical indentation in the end of a workpiece to mount a lathe center. Made of high-speed steel, these center drills are of high hardness and good wear resistance. There are 5 pieces of center drills in this set that can be used to drill holes of different sizes. Widely used on lathe machines, these center drills can cut easily and remove chips smoothly. Application: Center and spotting drills are traditionally used to form a conical hole for a lathe center in order to make a starting point for a standard twist drill. Designed to prevent the twist drill from walking. Used for producing center mounts in components or workpieces that require machining between centers. Note: When using these drills, the temperature of the material (e.g., soft metal, mild steel, aluminum, acrylic plastic, and wood, etc.) will be very high, please add water or coolant to prevent the product from smoking during use.