While chipping, The clearances angle is the angle between

0.8 mm

For conduit and other thin tubing, sheet metal work etc. use a 0.8 mm pitch.

1.8 mm

For soft materials such as bronze, brass, soft steel, cast iron, heavy angles etc. use a 1.8 mm pitch blade.

Drift

The taper shank drill should be removed from the machine spindle by means of tool called drill drift.

Arbor

The drill chucks are held on the machine spindle by means of an arbor fitted on the drill chuck.