1" 60° HSS 3-Flute Countersink 60° 4-Flute Countersinks while the round shank makes

while the round shank makes them compatible with various tool-holding systems

4-flute countersinks

These are jobber (standard) length drill bits with a black and gold surface treatment

Flute Length: 3"

and they provide a smooth finish on materials such as aluminum

1" 60° HSS 3-Flute Countersink 60° 4-Flute Countersinks while the round shank makesSpecifications SIZE 1" OVERALL LENGTH 3 1 2" MATERIAL HIGH SPEED STEEL FINISH UNCOATED (BRIGHT) SHANK DIAMETER 1 2" NUMBER OF FLUTES 3 SHANK TYPE ROUND CUTTING ANGLE 60 SUGGESTED PACK QTY 1 3 flute countersinks, also known as center reamers, are commonly used to countersink holes for centers or to enlarge existing holes.