HOBBING TOOL FOR FINISHING GEARS

摘要

A hobbing tool made of cermet composed of 70 to 97 per cent by weight of hard phase and a binder phase. The hard phase is made of a composite carbonitride of transition metals including titanium and tungsten, and at least one other element. The binder phase contains nickel and/or cobalt and inevitable impurities. The ratio between nitride atoms and carbon atoms and the ratio between titanium atoms and the atoms of transition metals other than titanium in the hard phase should be within specific ranges. The cermet having the above composition has an increased toughness and an excellent resistance to heat and wear and is difficult to weld.