The blank at the back end of the three-jaw pliers with one end is 3-4 mm long, and two step circles are processed to size. At the other end, the rotating step circle, the rotating sleeve and the rotating circle are matched and fixed on the panel with screws. At the same time, the screws are also used to fix the machined second ring and bottom surface, nuts, fixing sleeves and other workpieces. What do you want to do slowly? At the same time, the fixed position deviates from the center and the distance between the two columns is equal, and the columns to be processed are at the same time. Look at mining,