DEEP HOLE DRILLING
Several different processes can achieve deep-hole drilling. Trepanning cuts a narrow grooved surface in to a workpiece. Gun drilling is a quick and efficient method of producing deep or shallow close tolerance holes with smooth surface finishes – usually in one pass. The boring process uses a lathe, boring machine, or boring mill to make or enlarge a cylindrical hole.
Jig boring is a precision machining process that includes centering, drilling, reaming, counter boring, contouring, through-boring and step boring. Jig boring machines are similar to jig grinders, but use boring tools instead of high-speed grinding wheels.