1) After the new grinding rod is bonded, it must be "rounded" on the cylindrical grinder, especially the diamond grinding rod. If not rounded, tens of thousands of products are needed for normal use. Rounding is to clamp the grinding head with tooling, lift the grinding bar, and then smooth the grinding bar (average). Generally, the grinding head comes with this tool. When grinding, pay attention to correct the excircle of the grinding head first. It should be noted that the rounded grinding bars can't all arrive evenly, so we still need to pre-grind some workpieces for final correction. 2) The quality of the workpiece fixture will also seriously affect roundness and cylindricity. The fixture must be calibrated, and its coaxiality and verticality shall not be greater than 0.02. 3) cylindricity is also related to the itinerary of your school, so it needs to be adjusted.