Countersinking
Countersinks
Available in a range of sizes and versions
603060 90° Countersink
6.3mm to 31mm Diameters
603070 Drillsink
A very effective combination drill and countersink
12.4mm to 25mm (M6 to M12)
Versadrive Countersinks & Drillsinks work well on Impact up to 16.5mm diameter.
Larger sizes than this should be used in a pistol drill
There are also a range of larger countersink and multisink options in from 40 to 80mm diameter