4-20mm HSS M35 Cobalt Spiral Grooved Step Drill Bits 1/4'' Hex Handle 9 Sizes

M35 co high speed steel step drill bits, higher quality and more durable than HSS 4241 step drill bits. High speed cobalt steel along with titanium coating ensures extreme durability, it will stay new and shiny for years to come. Hex shank diameter: 6.35mm. No need center punch, compared with ordinary twist drill bit, it is not easy to break and it can be used for deburring, chamfering and opening hole. M35 co high speed steel step drill bits, higher quality and more durable than HSS 4241 step drill bit. Effective as a great cobalt drill bit. Made of super strong HSS steel for extra durability and longer life. Non-walking drill tip provides fast and smooth drills on steel sheet, aluminum sheet, wood board, plastic board, etc. (The board should be smaller in thickness than the height of the step drills).Size:4-20mmFeatures:Material: High Speed Steel, Co (HSS co M35)Surface Treatment: Titanium CoatedHex Shank Diameter: 6.35mm/1/4"Dimension: 4-20mm (4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm);9 StepsFeatures:Titanium coated to reduce mit and heat.Step drill bit made of high speed steel co M35, better quality and more durable than HSS 4241 step drill.Effective punch as an excellent cobalt drill bit.Very useful for drilling and especially punching holes in stainless steel, metals, plastics and wood.Suitable for drilling holes in sheet metal, steel plate, aluminum plate, brass or woodHighly recommended tool to have in the workshopAbout Trepanning for Stainless Steel Sheets:1. Both hand drill and bench drill can be used when trepanning stainless steel sheet, hand drill steel sheet within 1mm, and bench drill can drill 2-3mm steel sheet2. It is necessary to drill at low speed when trepanning stainless steel sheet, hundreds of rpm is okay.3. Please water it for cooling during punching to extend its service life, 250-400 rotation rate is recommended.Note:-At the trepanning, please wear good protective measures, in case of wood chips splashing.-Size for manual measurement, there may be a 0-3mm error, belongs to the normal phenomenon.-The knife is quite sharp, keep away from children.-In Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package List: 1 * M35 Hex Shank Step Drill Bit