On the principle of continuous indexing, the model YA31200H general-purpose gear hobbing machine is suited to cut cylindrical spur and helical gears, sprockets and wormwheels with manual radial feed . The model YKA3120 Z-axis CNC gear hobbing machine is developed based on the model YA31200H machine .Its CNC axes: X-axis radial feed and Z-axis feed. It can work in the conventional or climb method. It is capable of cutting wormwheels with radial or tangential feed driven by motor (tangential hob head is supplied on special order). The machine is equipped with an automatic shut down device, safety device and an automatic lubrication system. It is characterized by consistent working accuracy, good static dynamic and rigidity. It produces the workpiece in compliance with Accuracy Test Standard GB/T8064-1998 of Gear Hobbing Machine, and the finishing machining accuracy can be up to grade 7 of Gear Accuracy Standard GB/T10095-2008. The machine is best suited for hobbing large gears in induotries, such as mine,oil, marine, engineering mechanism, and etc.