The forming of gear teeth has traditionally been a time-consuming heavy stock removal operation in which close tooth size, shape, runout and spacing accuracy are required. This is true whether the teeth are finished by a second forming operation or a shaving operation.

It has previously been demonstrated that one gear of an interchangeable series will rotate with another gear of the same series with proper tooth action. It is, therefore, evident that a tooth curve driven in unison with a mating blank, will "generate" in the latter the proper tooth curve to mesh with itself.

Two major processes used for cutting gears, hobbing and shaping. This article describes advanced machine design and cutter materials for gear shaping.

Up until approximately 1968-69, pinion cutter-type gear shaping machines had changed very little since their conception in the early 1900's.