METHOD FOR PROCESSING CRANK SHAFT HALF

PROBLEM TO BE SOLVED: To solve the problem of a large number of machining stages in the conventional finishing work to a crank shaft half 14 having a pin hole 13 including processing to the pin hole 13 with an inner surface grinding machine and processing to a shaft part 57 with a separate outer surface grinding machine, in which the crank shaft half 14 need be transferred to be aligned each time. SOLUTION: Fig. (a) shows machining to the pin hole. The crank shaft half 14 is aligned to a rotary main shaft 29, it is clamped by clamp means 31 and 32, and the pin hole 13 is processed by a tool 26, while a grinding wheel 56 is held stand-by. Fig. (b) shows processing to the shaft part, where the crank shaft half 14 is kept as it is, while the tool 26 is held stand-by. Next, the crank shaft half 14 is rotated at high speed, and the grinding wheel 56 is applied to process the shaft part 57. Processing to the shaft part of the crank shaft half and processing to the pin hole provided at an eccentric position from an axial center can thus be executed without removing it from the processing device once it is set on it. The machining stages can be largely reduced.