1. Burns: Caused by excessive feed rate, insufficient coolant, too fine abrasive grit, too hard a bond, and high temperatures in the grinding zone.

2. Clogging and blunting: Caused by improper abrasive selection, improper bond selection, too fine a grit, or dull grinding wheel.

3. Chatter marks: Caused by spindle wear, loose grinding wheel clamping, too hard a grinding wheel, 

too fine a grit, excessive feed rate, wheel runout, uneven texture, and unbalanced grinding wheel.

4. Scratches: Caused by large particles in the abrasive and a soft grinding wheel.

5. Rapid grinding wheel wear: Caused by excessive feed rate, insufficient coolant, improper abrasive and bond selection, 

loose bond texture, using a wet grinding wheel for dry grinding, or a too soft grinding wheel.