3pcs Spiral Step Drill Bit[4-12/4-20/4-32mm,Total 32 Sizes], Cone Hex Shank Titanium Coated High Speed

[29 Sizes]: 3 standard size step drill bits have the following 32 sizes: 15 steps: 4-32mm (4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 30mm, 32mm); 9 steps: 4: 4mm (4mm, 4mm, 6mm, 4mm, 6mm, 8mm, 4mm, 8mm, 4mm, 6mm, 8mm, 4mm, 6mm, 8mm, 4mm, 4mm, 6mm, 8mm, 6mm, 8mm, 10mm, 10mm. 2mm, 14mm, 16mm, 18mm, 20mm; 5 steps: 4-12mm (4mm, 6mm, 8mm, 10mm, 12mm) A variety of drill bit sizes are perfect for your needs and save your time. [Premium Material]: These step drill bits are made of heat treated 4241 high speed steel with titanium nitride coating.Titanium coating to reduce friction and operate cooling, can effectively extend the service life.Ladder structure: one drill bit can drill holes of different specifications, no need to buy multiple drill bits, saving space and money.Spiral slot: provides faster, smoother cutting and tri-flat shank to ensure firm grip. Triangle round shank: can be easily inserted into drill, drill and press drill.Suitable for: The step drill bit set can be used for workpieces with hardness less than 25° and thickness less than 5mm. Suitable for a variety of materials, such as carbon steel, sheet metal, insulation boards, PVC boards, wood, etc. They also help to widen existing holes. Not recommended for stainless steel. Instructions for use: 1) Low speed star drilling. Don't push too much.Let the bit cut by itself. The harder the material, the lower the speed.2) Inject cooling oil while working, it will greatly increase the drilling efficiency and extend the life of the drill bit.3) Drill bits are good for drilling wood, plastic, steel and sheet metal. Stainless steel is not recommended.Sold by Bianco FR store