TurningMillingDrillingTechnicalInformationIndex Technical information Trouble shooting – drilling A Trouble shooting – solid carbide drillsError Reason Countermeasure Excessive wear – Overdue regrinding – Regrind in time – Drill tip not in centre position – Adjust drill with centre of spindle – Cutting speed too high – Reduce cutting speed – Cutting angle not suitable – Chose right cutting angle – Material not suitable – Chose suitable material B – Insufficient cooling – Use suitable cooling Wear and chipping on point relief – Feed rate too high – Reduce feed rate – Cutting angle not suitable – Chose right cutting angle – Material not suitable – Chose suitable material – Clearance angle too small – Regrind drill Breakage on margin – Guide bush too large – Change guide bush Built up edge on margin – High wear and heat – Regrind drill C – Insufficient cooling – Change cooling method – Wrong coolant – Change coolant – Workpiece material is too soft – Use drill with smaller clearance angle High vibrations – Clearance angle too large – Regrind drill – Drill stability too low – Improve stability Swarf clogs the drill – Long chips – Optimise cutting data – Chip removal not fluent – Change drill or adjust machine D One-side wear – Drill tip not centred – Adjust drill with centre of spindle – Poor clamping – Improve drill clamping – Check concentricity E C 168