After completion of one or two teeth, the blank and cutter stop feeding and the cutter is withdrawn and indexed back again to its starting position, thus enabling a short rack cutter of a practical size to be utilized. Cutter is once again fed back again to depth and cycle is repeated. Quantity of teeth is controlled by the machine gearing, and pitch and pressure position by the rack cutter. This method is utilized for gear rack for Machine Tool Industry china generation of external spur gears, being preferably fitted to cutting large, double helical gears. For creating helical teeth, the cutter slides tend at the apparatus tooth helix angle.
The hob 
is fed into the gear blank to the proper depth and both are rotated together as if in mesh. One’s teeth of the hob cut in to the work piece in successive order and each in a somewhat different placement. Each hob tooth cuts its profile based on the shape of cutter , but the accumulation of these straight cuts generates a curved kind of the gear teeth, hence the name generating procedure. One rotation of the task completes the trimming upto particular depth upto which hob is definitely fed unless the gear has a wide face.
This methodis specially adopted to cutting large teeth which are tough to cut by formed cutter, and also to cut bevel-gear teeth. It isn’t widely used at the moment.
In gear planing process, the cutter includes accurate involute rack which reciprocates across the face of the blank and the blank rotates in the right relationship to the longitudinal movement of the cutter as though both roll together as a rack and pinion. At first the cutter is fed into full tooth depth with cutter reciprocating and blank stationary. Involute shape 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 usage of the formed tool for finishing is definitely impracticable for the bigger pitches which are finished by an individual pointed tool. The number of cuts required is dependent upon the size of the tooth, amount of stock to be removed, and the type of material.