A. Process system vibration, machine tool vibration and unstable pressure in hydraulic system. The grinding amount will increase at the moment of vibration, causing burns. At this time, the burns are distributed along the surface of the workpiece in the form of vibration lines, also known as vibration line burns.

B. Poor grinding wheel dressing makes the abrasive not sharp, causing burns. At this time, the burns are distributed along the grinding wheel wear marks, also known as scratch burns.

C. The centerless fixture has insufficient suction or loose support, and the workpiece will slide instantly, causing burns.

D. Uneven grinding amount and inconsistent grinding thickness will cause local burns.