| Trouble | Occurrences | Countermeasures |
| Too high feed | Reduce feed |
| Up milling | Change down milling |
| Chipping | Sharp cutting edge | Honing at the cutting edge-chamfering or rounding if needed |
| Chattering | Check spindle speed down |
| Too much overhang | Adjust to minimize overhang |
| Unfixed chucking of Endmill | Check the precision of chuck and collet |
| High Cutting speed | Decrease cutting speed |
| W | Low feed | Increase feed |
| ear | Up milling | Down milling |
| High-hardened work piece | Choosing special coating endmill |
| Too much cutting amount | Decrease cutting amount |
| Tool Breakage | High cutting force | Feed down; spindle speed up |
| Too much overhang | Adjust to minimize overhang |
| Chattering | Change the cutting condition |
| Surface Roughness | Generation of built-up edge | Increasing cutting speed & Feed rate or down milling |
| high feed, low speed | Reduce feed & Increase speed |
| i | Incorrect Numbers of flute | Replace more flutes Endmill |
| Accuracy of finished work piece | Deflection of Tool | Using big diameter tool & Minimize the overhang |