The process of forging metal into shapes possesses
a surprisingly long and storied history.
For example, the method of hot rolling can trace its protracted existence all the way back to an enigmatic Italian polymath named Leonardo da Vinci (you may have heard of him), who reportedly invented the rolling mill one lazy day in the 1400s.
The term "blanking" refers to the initial metal cutting operations in the process planning sequence which produce the contour of a part starting from rough material.
The scope of blanking is:
To remove the excess material
To machine the part to print specifications, except for those surfaces with subsequent finishing operations.
To leave adequate machining stock for finishing operations.
To prepare good quality surfaces for location and clamping of the part throughout the process.
The quality of the finished gear is influenced by the very first machining operations of the blank. Since the gear tooth geometry is generated on a continuously rotating blank in hobbing or shaping, it is important that the timed relationship between the cutter and workpiece is correct. If this relationship is disturbed by eccentricities of the blank to its operating centerline, the generated gear teeth will not be of the correct geometry. During the blanking operations, the gear's centerline and locating surfaces are established and must be maintained as the same through the following operations that generate the gear teeth.