For cylindrical parts such as pins, shafts, and spacers, or parts with general rotational symmetry,in another words, parts design with symmetrical cylindrical or spherical features,‘turning’ them on a lathe is usually the simplest and most cost effective choice. Contrary to cnc milling, a lathe operates by fixturing cylindrical stock, called a rod, into a rotating chuck jaw on the machine. As this chuck rotates at a high RPM, so does the stock, and a fixed-orientation tool then translates along and across the stock to cut part features.