Thermal cracks

Decrease feed per tooth [fz]
Increase cutting speed [Vc]

Chipping of the cutting edges

Decrease feed per tooth [fz]
Control rigidity machine, workpiece and fixture
Change to climb milling
Minimize overhang

Fatal breakage

Increase cutting speed [Vc]
Decrease feed per tooth [fz]
Decrease depth of cut [Ap]
Minimize overhang
Optimize chipflow by coolant air pressure
Decrease width of cut [Ae]

Wear on relief angle

Increase feed per tooth [fz]
Decrease cutting speed [Vc]
Use coated grade

Built up edge

Increase cutting speed [Vc]
Increase feed per tooth [fz]
Optimize coolant flow
Check emulsion percentage

Chattering

Optimize workpiece fixture
Change to climb milling
Change to other cutting geometry
Decrease metal removal rate [Q]

Bad workpiece surface

Increase cutting speed [Vc]
Optimaze rigidity
Use multi-fluete endmills
Use higher helix angle