Spiral Grooved Step Drill Bit Set, Hex Shank Metric Bearing Steel Titanium Plating Spiral Pagoda Drill Bit Set, Drill and Enlarge Hole for Plastic Wood and Soft Metal

• 【Two-Flute Step Drill Bits 4-piece Set】3-Piece Spiral Groove Step Drill Bit (4-12 mm, 4-20mm, 4-32mm) + 1 Automatic Center Punch. 1/4" Hex shaft drives are suitable for all kinds of for home DIY power drills.
• 【Double Groove Spiral Design】Step drill bit adopts spiral double cutter design, realizing faster, more stable and smoother cutting.It can automatically chamfer the hole to clean the drill bits,and the step tool is automatically deburred from the hole when the drill bit is drilled
• 【Convenience】Step drill bits allows to cut several sizes hole with one drill bit, easily without changing bit constantly.
• 【Titanium Plating】The titanium plating makes it easier to drill materials and also gives an improved tool life. Where possible use coolant to increase the tool life even further.
• 【Wide Application】Perfect step drill bits suitable for drill and enlarge holes in various material： within 3mm/0.2 inch (Iron Plate, Copper Plate, Aluminum Plate); within 5mm/0.2 inch (Wood, PVC sheet, Insulation Boards). Not suitable for hard and brittle materials such as stainless steel, glass, tile floors, walls etd.

TIPS: 1. The 12V lithium electric drill has insufficient torque and is not recommended for use. It is recommended to use 36V and 48V lithium electric drills. 2. The larger the diameter of the hole, the lower the speed of the drill. It is recommended that the speed be within 1000RPM.