Hardened gear heat treatment prior to the preamble of the hob cut out the whole tooth, thus shaving gear hob tooth portions only make micro cutting. Easy to wear a top edge portion of the tooth is not involved in cutting, only the side cutting edge involvement. Since a thin layer of metal is cut away from the tooth form high hardness, hob left and right side of the cutting edge teeth engaging simultaneously is varied, it is difficult to ensure teeth left, consistent with the right amount of cutting surface of the cutting. Cutting force (especially along the hob axial component) cyclical fluctuations can easily cause vibration hobbing machine, so the knife to slip, leading to rapid wear or chipping hob.

At home and abroad generally use large negative rake angle carbide hobbing hardened gear. Carbide hob hardness and wear resistance is better, but poor toughness and thermal cracking performance. The following terms of machines, tools, fixtures, gear blanks, cutting fluids, cutting parameters one by one to discuss how to take full advantage of this cutting method.