Grinding and superfinishing are performed in parallel with each other on at least a portion of {TAIL ~ object portions}, thereby shortening machining time per {HEAD ~ workpiece} 
Grinding and superfinishing are performed in parallel with each other on at least a portion of { TAIL ~ object portions } , thereby shortening machining time per { HEAD ~ workpiece }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD