3Pcs/Set Hexagonal Shank High-speed Steel Step Cone Dril Bits 3-12mm/4-20mm/4-12mm Hole Cutter with Pouch

Features:
Automatically deburrs holes as you drill.
Two-flute design gives you faster, smoother cutting.
Titanium nitride coating for cooler running.
Quick-change 1/4 hex shank.
Manufactured from high speed steel for increased durability and cutting power.
Used for variety of materials from metal, plastic, fiberglass to wood.
They also help to enlarge existing holes.