Protuberance hobs

Hobs with protuberance are roughing cutters whose profile differs from the standard type to DIN3972 in that protuberances are present on the tips which project beyond the straight flanks of the basic profile.

The purpose of the protuberance hobs is to create a clearance cut on the tooth roots of spur gears, This is necessary when the teeth are to be finish machined by shaving, grinding or hobbing with a carbide skiving hob.