Posted by Ron V on November 14, 2009 at 20:03:53:
In Reply to: Topping hob question posted by Jim Pollock on November 14, 2009 at 18:46:44:
A semi topping hob is not meant to cut or top the O.D.
They are for applying a tip chamfer or tip radius.
They are generally designed for applying a measure of these modifications to a specific number of teeth.
Tip chamfering is very common on major or minor diameter fit splines.