Step Drill Bit Set Metric 3PCS with Bag, Automatic Center Punch (4-12mm/4-20mm/4-32mm), 1/4" Hex Shank Quick Change Titanium Coated High Speed Steel Drill Bits for Copper/Aluminum/Wood/Plastic - NewShark, E50020

• 【TITANIUM COATED MATERIAL】High speed steel and titanium coating ensure excellent durability and sharpness for less friction and cooler running. 【ENGRAVING DIMENSIONS】Easily identify the size you need by contrasting laser engraving dimensions in the grooves of the step drill bit: Bit #1 (5 steps): 4-12mm (4mm, 6mm, 8mm, 10mm, 12mm). Bit #2 (9 steps): 4-20mm (4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm). Bit #3 (15 steps): 4-32mm (4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, 32mm). 【IMPROVED CUTTING SPEED ​​DESIGN】 Split point tip at 118 degrees for increased wear resistance. The dual edge design provides a smoother cut and allows material particles to easily escape for a cleaner drilling operation. 【SATISFY YOUR NEEDS】We provide step drills, you can machine holes of different diameters, which greatly saves you a lot of trouble. Great for steel, aluminum, copper, plastic, wood and many other types of metal, easy to countersink. 【WIDE RANGE OF APPLICATIONS】Ideal for sheet metal, aluminum, wood chips, plastic and wood. It is perfect for DIY and engineering use.