After completion of 1 or two teeth, the blank and cutter stop feeding and the cutter is withdrawn and indexed back again to its starting position, thus allowing a short rack cutter of a practical duration to be used. Cutter is once again fed back to depth and cycle is repeated. Number of teeth is controlled by the device gearing, and pitch and pressure angle by the rack cutter. This method is used for generation of external spur gears, being preferably fitted to cutting large, double helical gears. For generating helical the teeth, the cutter slides are inclined at the gear tooth helix angle.
The hob is fed 
in to the gear blank to the proper depth and the two are rotated together as though in mesh. One’s teeth of the hob cut in to the function piece in successive purchase and each in a somewhat different placement. Each hob tooth cuts its own profile based on the form of cutter , but the accumulation of these directly cuts creates a curved kind of the gear teeth, thus the name generating procedure. One rotation of the work completes the trimming upto certain depth upto which hob is certainly fed unless the gear has a wide face.
This methodis specifically 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 the moment.
In gear planing procedure, the cutter consists of true gear rack for Machine Tool Industry 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 jointly as a rack and pinion. At first the cutter is usually fed into full 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 completing cuts are taken with single pointed tools. The use of the formed tool for finishing can be impracticable for the larger pitches which are completed by an individual pointed tool. The amount of cuts required is dependent upon how big is the tooth, amount of share to be eliminated, and the type of material.
