A five piece set of heat treated tool steel countersinks with hex shafts,they are adjustable for different length screws and will produce a 9.5 mm (3/8in) or 12.7 mm (½in) diameter counterbored hole to fit standard woodplugs.
2.0 mm (5/64in) Drill and C/S Size No.4.
2.4 mm (3/32in) Drill and C/S Size No.6.
2.8 mm (7/64in) Drill and C/S Size. No.8.
3.2 mm (1/8in) Drill and C/S Size.No.10.
3.6 mm (9/64in) Drill and C/S Size. No.12.

Fitted with High Speed Steel drill bits to cover the full range of screw sizes and are self clearing.