1. DURING ID BORING OPERATION PROCESS BORE OVERSIZE OCCURRED|2. THE EXCESSIVE HEAT GENERATION AND BUILT-UP EDGES CREATED ON THE INSERT WHICH CAUSE TO REMOVAL OF THE EXCESS MATERIAL|3. THE SUFFICIENT COOLANT NOT FLOWED ON THE PART DUE TO THAT BUILT-UP EDGES AND HEAT GENERATION CREATED|4. COLLANT FILTER BLOCKED DUE TO THAT COOLANT WAS NOT FLOWED PROPERLY