3Pcs Spiral Step Drill Bit Set with Automatic Spring Loaded Center Punch

[Widely Used]Perfect Step Drill Bits suitable for drill holes in various material: within 3mm/0.12 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 etc.

[Material]HSS combined with a titanium coating. More capable and durable.

[Easy Drilling]Two-Flute Design for smoother cutting. High Step design let you feel the stop and never drill bigger in mistake

[SET INCLUDES]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)

[Package Includes] 3-Piece HSS Groove Step Drill Bit (4-12/ 4-20/ 4-32mm ) + 1 Automatic Center Punch. 1/4" Hex shaft drives are suitable for all kinds of for home DIY power drills.