After completion of one or two teeth, the blank and cutter stop feeding and the cutter is withdrawn and indexed back again to its starting position, thus allowing a brief rack cutter of a practical gear rack for Machine Tool Industry length to be used. Cutter is once again fed back again to depth and cycle is repeated. Amount of teeth is managed by the machine gearing, and pitch and pressure position by the rack cutter. This method is utilized for generation of exterior spur gears, being preferably fitted to cutting large, double helical gears. For generating helical tooth, the cutter slides tend at the gear tooth helix angle.
The hob is fed into the gear blank to the correct depth and both are rotated together as though in mesh. The teeth of the hob cut in to the work piece in successive order and each in a somewhat different position. Each hob tooth cuts its profile based on the shape of cutter , however the accumulation of these directly cuts creates a curved type of the gear teeth, hence the name generating process. One rotation of the work completes the slicing upto specific depth upto which hob is fed unless the apparatus has a wide face.
This methodis specially adopted to cutting large teeth which are tough to cut by formed cutter, and to cut bevel-gear teeth. It isn’t widely used at present.
In gear planing procedure, the cutter includes true involute rack which reciprocates across the face of the blank and the blank rotates in the right relationship to the longitudinal motion of the cutter as if both roll with each other as a rack and pinion. Initially the cutter can be fed into complete tooth depth with cutter reciprocating and blank stationary. Involute form is produced as the blank rotates and involute rack cutter feeds longitudinally.
In the other technique, both roughening and completing cuts are taken with single pointed tools. The usage of the formed tool for finishing is certainly impracticable for the bigger pitches which are completed by a single pointed tool. The amount of cuts required is 
dependent upon the size of the tooth, quantity of stock to be eliminated, and the kind of material.