After completion of one or two teeth, the blank and cutter stop feeding and the cutter is withdrawn and indexed back to its starting position, thus enabling a short rack cutter of a practical size to be used. Cutter is once again fed back again to depth and cycle is repeated. Quantity of teeth is controlled by the device gearing, and pitch and pressure angle by the rack cutter. This technique is utilized for generation of exterior spur gears, being ideally gear rack for Machine Tool Industry china suited for cutting large, dual helical gears. For making helical tooth, the cutter slides are inclined at the gear tooth helix angle.
The hob is fed into the gear blank to the proper depth and the two are rotated together as though in mesh. The teeth of the hob cut into the function piece in successive order and each in a slightly different position. Each hob tooth cuts its own profile depending on the shape of cutter , however the accumulation of these straight cuts generates a curved type of the gear teeth, thus the name generating process. One rotation of the work completes the trimming upto certain depth upto which hob is usually fed unless the apparatus has a wide face.

This methodis specially adopted to cutting large teeth which are difficult to cut by formed cutter, and to cut bevel-gear teeth. It is not widely used at present.
In gear planing procedure, the cutter includes accurate involute rack which reciprocates across the face of the blank and the blank rotates in the correct relationship to the longitudinal movement of the cutter as if both roll collectively as a rack and pinion. Initially the cutter can be fed into full tooth depth with cutter reciprocating and blank stationary. Involute form is generated as the blank rotates and involute rack cutter feeds longitudinally.

In the other method, both roughening and completing cuts are taken with single pointed tools. The use of the formed tool for finishing is usually impracticable for the bigger pitches which are completed by an individual pointed tool. The number of cuts required depends upon the size of the tooth, quantity of share to be removed, and the kind of material.