Step Drill Bit, Metal Countersink Drill Bit 4PCS 4-12/20/32mm Step Drill Bit Steel Countersink Drill Triangle Conical Drill with Titanium Coating Screwdriver Drilling for Steel/Wood/Brass/Plastic/PVC [ Robust and Rustproof] Made of high quality HSS, it cuts thin materials quickly. HSS provides extreme durability, and the drill bits are rust-proof. At the same time, our drill bit is suitable with electric screwdriver [Application]Step drill bit suitable for DIY, home and construction. It is very suitable for drilling holes in a variety of materials like steel/brass/wood/plastic/thin iron plate/aluminum materials/insulating plate/PVC plate, etc. Only suitable for ordinary aluminum, iron and steel plates (thickness cannot exceed 4mm, hardness is less than 25HRC), not for stainless steel < /p> [Twirl Drill Bit]With 4mm 6542 Twist Drill Bit can pre-drill materials, which makes the step drill bit less easily damaged than ordinary step drill bit. Note: Oil the step bits before each use to maximize life. 3PCS Step Drill Bits (4-12mm/20mm/32mm) with 4mm Twist Drill Bit - High speed steel auger made of high quality hardened steel - The coating uses a titanium alloy coating to reduce friction and heat - Suitable for DIY, home and general construction/engineering. Can be used for wood, sheet metal, steel and other surfaces Note --- Before use, it is necessary to install a fixed clamping hexagonal rod to avoid the occurrence of swinging and tension in the groove, etc., to avoid the risk of cracking. Chute and so on -----Step drills suitable for DIY, home and construction. The material is only suitable for ordinary aluminum, iron and steel plates Product specifications: Material: Steel Length: 4-12mm length: about 7.2cm 4mm twist drill Length: about 7.2cm Size: 4-32mm (4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, 32mm) 4-20mm (4mm , 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm) 4-12mm (4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm , 12mm) Sold by the grid cool store