1. Burns: Caused by too much feed, insufficient coolant, too fine grinding wheel particle size, too hard binder, and high temperature in the grinding area.

2. Clogging and lack of sharpness: Improper selection of abrasives, improper selection of binders, too fine particle size, and blunt grinding wheels.

3. Vibration marks: The spindle is worn, the grinding wheel is not clamped tightly, the grinding wheel is too hard, the grain size is too fine, the feed rate is too large, the grinding wheel jumps, the structure is uneven, and the grinding wheel is unbalanced.

4. Scratches: There are large particles in the abrasive and the grinding wheel is soft.

5. The grinding wheel is consumed quickly: too much feed, insufficient coolant, improper selection of abrasives and binders, too loose binder structure, wet grinding wheels for dry grinding, grinding wheels that are too soft, etc.