The part given in the title is the fork 83 1022 of the operating mechanism of the friction clutch in the lathe spindle box. It is located in the speed change mechanism of lathe, which mainly plays the role of shifting gears, so that the spindle rotation can work according to the requirements of workers and obtain the required speed and torque. The φ25 hole above the part is connected with the operating mechanism, and the φ60 half hole below the second part is used to contact the shaft where the controlled gear is located. The lower gear is shifted by higher force. These two parts are cast as a whole and separated during processing.