Step Drill Bit for Metal, Step Drill Bit, CORTOOL Titanium High Speed Steel Step Drill Bit Set, Unibit Step Drill Bit, Step Drill Bit for Metal, Heavy Duty Step Bit (1/8" to 1/2" Step Bit) Two-fluted design provides faster,smoother cutting,provided with small pressure and the sets. The 3-flat shank titanium drill uses a doubleedged design to make cutting smoother and smoother;Increases cutting speed with self-centering and prevents walking. Perfect for home repairs and light jobs such as drilling holes in plastic, aluminum, copper, iron sheet and many other types of sheet metal (excluding steel or any other harder metal). 7 steps cone drill bit: 1/8, 3/16, 1/4, 5/16, 3/8, 7/16, 1/2 inch. Your customer satisfaction and 30-day warranty of step drill bit can be guaranteed.