Application of high speed slurry flow finishing method for finishing of inner wall of fine hole die: Effects of the hardness of die material on the polishing characteristics

In order to warrant the quality of drawn metal wires, the inner wall of the hole die which has been used in the drawing of metal wire, has been usually finished by hand work for a long time using a bar daubed the kneaded paste containing diamond powder. High speed slurry flow finishing method which has been recently developed for the finishing of inner wall of capillary has been applied to the finishing of the hole die. It is found that the surface roughness of inner wall of the hole decreases with the increasing number of slurry flow pass in a relatively short finishing time, and that surface roughness reduction rate depends on the hardness of die materials. Experiments show that the bell mouth shape is spontaneously formed in the high speed slurry flow finishing.