Drilling uses diameter, cutting speed, RPM and feed per revolution differently from milling. This reference explains the variables and the checks that matter for hole-making.
Drill RPM
Calculate RPM from cutting speed and drill diameter using the appropriate metric or imperial equation. Check the result against the spindle range.
Feed per revolution
Drill feed is commonly expressed in feed per revolution. Programmed feed follows F = RPM × f/rev. This makes unit discipline important.
Hole depth and chip evacuation
Deep holes can require pecking, coolant delivery and chip-evacuation strategies that are not represented in the basic feed equation.
Tool condition
Drill point geometry, diameter tolerance, holder runout and material condition influence the actual cut. Use the drill manufacturer’s data.
Related tools
See the Spindle Speed Calculator and drilling trade tools for operation-specific checks.