Gear hobbing is not a gear finishing process.

Gear hobbing is a gear manufacturing process that involves the use of a hob, which is a cylindrical cutting tool with helical teeth. During gear hobbing, the hob is mounted on a hobbing machine and it rotates while the gear blank is slowly fed against it. As the hob and gear blank rotate, the teeth of the hob gradually cut into the blank, creating the desired gear teeth.

Gear hobbing is a primary gear manufacturing process, not a finishing process. It is typically used to generate the initial gear teeth profile before any finishing operations are performed. The process is capable of producing gears with high accuracy and good surface finish, but it may leave some residual imperfections on the gear teeth surface.

Gear finishing processes, on the other hand, are used to improve the surface finish and dimensional accuracy of gears that have already been formed. These processes are often performed after gear hobbing or other primary gear manufacturing processes. Some common gear finishing processes include gear shaving, gear lapping, and gear grinding.

Gear shaving is a gear finishing process that involves removing a thin layer of material from the gear teeth surface using a shaving cutter. This process helps to improve the surface finish, reduce gear noise, and ensure proper gear tooth contact.

Gear lapping is another gear finishing process that uses a lapping tool, typically a cast iron or bronze wheel, along with a fine abrasive paste to remove small amounts of material from the gear teeth surface. This process helps to improve the surface finish, eliminate any remaining imperfections, and ensure proper gear meshing.

Gear grinding is a gear finishing process that involves the use of a grinding wheel to remove material from the gear teeth surface. This process is used to achieve high precision and tight tolerances, as well as improve the surface finish and gear tooth profile.

In summary, gear hobbing is not a gear finishing process but a primary gear manufacturing process. Gear finishing processes, such as gear shaving, gear lapping, and gear grinding, are performed after the gears have been formed to improve their surface finish and dimensional accuracy.