PATIKIL 4mm Drill Bit, Jobber Straight Shank M35 Cobalt 5% High-Speed Steel 135° Gold Finish for Stainless Steel Hard Metal - 5 Pack

PACKING LIST: 5 packs of drill bits in 4mm cutting diameter, 43mm/1.69inch flute length, 75mm/2.95inch overall length, 135° split point tip.

FEATURE: The drills are made of M35 high speed steel with 4.50% to 5.50% cobalt content, which has excellent hardness, wear resistance, heat resistance and high crack resistance, making it suitable for machining hard metals. The gold finish effectively improves corrosion resistance and extends the drill bits' life.

APPLICATION: The M35 twist drill is suitable for professional machining, particularly for drilling stainless steel. It is also suitable for processing high-hardness materials, including carbon steel, iron, aluminum, copper, plastic, wood, and more.

NOTE: Position the twist drill bit at 90° to the surface of the workpiece. For thick materials, drill in multiple passes to prevent overheating or breakage. For large holes, start with a guide hole. Use cutting fluid to improve efficiency, extend tool life, and reduce material damage.

INSTRUCTION: When machining different materials, the spindle speed and feed rate vary. Generally, the harder the material, the lower the spindle speed and feed rate should be. For specific speed and feed rate recommend for common materials, please refer to the details provided on the product page.