Much Harder - M35 HSS is much harder than HSS 4241, suitable for drilling stainless steel plates and quenching steel plates, iron plates, aluminum, wood. Good Design: Triangular shank fits into power tool chuck securely and eliminates slippage. The two flute design removes chips faster and allows particles to escape easily. One step drill bit meets all your requirements, 4-32mm M35 HSS with 15 sizes: 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm , 22mm, 24mm, 26mm, 28mm, 30mm, 32mm The split tip increases speed. It can automatically deburr the holes while drilling to keep the drill bit clean. You can use water to cool it down when it works and it can be used even longer. Product High hardness: Meichoon M35 cobalt step drill bits are made of high speed steel with cobalt, which provides long service life. Features: 1. High speed steel for longer life. 2. The design of double cutting blades allows for faster and smoother cutting. 3. Advanced double spiral flute design outperforms straight flute design and extends bit life. The split tip increases speed, and it also includes laser-etched measurements to increase the visibility of not. 4. The sharpness makes it easy to cut through most sheet metal, plastic and other materials. Features: Material: high speed steel. Step Drill Sizes: 15 steps (4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, 32mm ). Content: 1 M35 HSS Co drill bit from 4 to 32 mm.