Ohip formation and chip evacuation are crical issues in driling and depend on the workpiece material. choice of drllinsert geomeiry, coolantpressure/volume and cuting data. hip jamming can cause radial movement of the dll and consequently affect hole auality, drllife and reiabityor drill/insert breakages.

       Chip formation is acceptable when the chips can be evacuated from the drillwithout disturbance.The best way to identify this is to listen duringdriling. A consistent sound means that chip evacuation is good, but an interrupted sound indicates chip iamming. Check the feed force or powemonitor, f there are iregulariies, chip jamming could be the reason. Look at the chips: if they are long and bent, instead of curled, chip jamming
has occurred. Look at the hole: if chip jamming has occurred, an uneven surface will be visible

Achieving good hole quality

Chip evacuation

Make sure chio evacuationis satisfactorv, Chio amming afects hole oualty and relablitvtoolie, pnlinsert aeometv and cuting data are crucia

Stability, tool set-up
use the shonest oossible drl. use a rioid and accurate toolholder with minimum run-out wake surethe macnine soindle is in good condition andis well-aligned. Ensure that the component is fixed and stable. Estabish correct feed rates for irregular, anqular surfaces and cross holes.