After completion of one or two teeth, the blank and cutter stop feeding and the cutter is withdrawn and indexed back to its starting position, thus enabling a brief rack cutter of a practical length to be utilized. Cutter is once again 
fed back again to depth and cycle is repeated. Number of teeth is controlled by the gear rack for Machine Tool Industry china machine gearing, and pitch and pressure position by the rack cutter. This technique can be used for generation of external spur gears, being ideally suited for cutting large, dual helical gears. For producing helical teeth, the cutter slides are inclined at the apparatus 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 in to the function piece in successive order and each in a somewhat different position. Each hob tooth cuts its own profile depending on the form of cutter , but the accumulation of these straight cuts produces a curved type of the gear teeth, therefore the name generating procedure. One rotation of the work completes the reducing upto particular depth upto which hob is definitely 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 also to cut bevel-gear teeth. It isn’t widely used at the moment.
In gear planing procedure, the cutter includes accurate involute rack which reciprocates over the face of the blank and the blank rotates in the right relationship to the longitudinal movement of the cutter as if both roll jointly as a rack and pinion. Initially the cutter can be fed into complete tooth depth with cutter reciprocating and blank stationary. Involute shape is produced as the blank rotates and involute rack cutter feeds longitudinally.
In the other method, both roughening and finishing cuts are taken with single pointed tools. The use of the formed tool for finishing can be impracticable for the larger pitches which are finished by a single pointed tool. The number of cuts required depends upon the size of the tooth, quantity of stock to be taken out, and the type of material.