These Faithfull Screwsinks can be used for drilling, countersinking and counter-boring in one operation. The countersinking part can be slid up and down the drill part of the tool by means of a hexagon key to suit the depth of hole being drilled.
Set of 4 Containing: No.6 (7mm), No.8 (8mm), No.10 (10mm), and No.12 (11.5mm).