Drilling is a method for creating or enlarging holes in a component.
When drilling, a drilling machine is lowered towards the workpiece. When the rotating cutting tool reaches the component, a hole is cut. The diameter normally ranges from 1/8 to 1½ inches, sometimes expressed in millimeter. It is possible to make larger or smaller holes, but it usually requires different production techniques. The ratio between the diameter and the depth of the hole ranges from 1:1 to 1:10. Although it is possible to do other ratios, it normally requires special tools. This is frequently used within the aviation industry.
There are a few different kinds of stationary drilling machines. Among them, the radial arm drill press is often considered as the most important in workshops. The workpiece remains fixed on a table while the spindle moves to where a hole is supposed to be drilled. This is typically for small volume production. Some workshops also have automated drilling machines that can drill several holes at the same time. In all cutting operations, a cutting fluid is normally used to reduce the negative effects of friction heat.
Drills are available at most workshops, although some workshops specialize in more advanced drilling projects.
Compare drilling with CNC drilling, which is used when the drilling has to be very accurate or in patterns. With deep hole drilling, it is possible to do very deep holes.