These countersinks are produced in High Speed Steel (HSS) and should not be confused with carbon steel types.
They are designed for countersinking mild steel iron and plastics.
Multi flute design.
Ground shank for greater running accuracy.

Specification:
D=12.5 mm
OL=40 mm
Shank length=19.5 mm
Shank Diameter=1/4 inch
Flutes=5