[Widely Used]Perfect Step Drill Bits suitable for drill holes in 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]High speed steel 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 Colour:Golden Material:High speed steel Package Contents: 1 x 4-12mm drill bit 1 x 4-20mm drill bit 1 x 4-32mm drill bit 1 x blue cloth bag Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.