6pcs HSS TiN coated Countersink Drill Bits set with Spiral Flute (arc groove)

6pcs HSS TiN coated Countersink Drill Bits set with Spiral Flute (arc groove)
6pcs HSS TiN coated Countersink Drill Bits set with Spiral Flute (arc groove)
The improved arc groove is highly compatible with the spiral groove,335C 90°, which greatly improves the working efficiency and prolongs the service life.
Because of the spiral flutes and arc groove the cutting edges are extremely sharp.  Ideal for burr- and chatter-free deburring and countersinking.  Applicable for steel, cast iron, non-ferrous and light metals.  Best results at low cutting speeds.

Size:6.3, 8.3, 10.4, 12.4, 16.5, 20.5mm