Drill bits set Bosch HSS Twist Drill Bits Cobalt 2608585862 – HSS cobalt twist drills for metal

HSS Twist Drill Bits Cobalt by Bosch are high-speed steel twist drills enriched with around 5% cobalt alloy, designed specifically for drilling into metal and other hard materials. Fully ground to DIN 338 standards and featuring a Type N flute geometry with a 135° split-point tip, these drill bits deliver accurate centring, consistent cutting action and reduced wandering. The cylindrical shank matches the drill diameter for secure clamping in drill stands and hand-held drill drivers, while two cutters and two flutes ensure efficient chip evacuation and prolonged tool life when machining alloyed and non-alloyed steel, stainless steel, cast iron and heat- or acid-resistant steels.

Advantages

These HSS cobalt twist drills offer improved heat resistance and wear durability compared with standard HSS bits, resulting in extended lifetime under heavy-duty metalworking conditions. The fully ground body provides smooth surface quality and precise dimensions with h8 diameter tolerance, and the split-point 135° tip enables immediate engagement without pre‑centering in many applications. Efficient chip removal from the dual-flute geometry reduces clogging and helps maintain cutting performance throughout use.

Suitable for

• Drilling stainless steel and alloyed steels
• Working with cast iron and cast steel
• Applications involving heat- and acid-resistant metals
• Workshop, maintenance and construction metal‑drilling tasks
• Use in drill stands and hand-held drill drivers

Key specifications

• Material: High-speed steel with approximately 5% cobalt alloy
• Manufacturing/standard: Fully ground to DIN 338
• Tip geometry: Split-point tip with 135° angle for reduced wandering
• Flute type: Two cutters and two flutes for efficient chip evacuation
• Shank: Cylindrical shank matching drill diameter for secure clamping
• Tolerance: Diameter tolerance h8 for accurate fit and repeatability
• Intended materials: Alloyed and non-alloyed steel, stainless steel, cast iron, cast steel, heat- and acid-resistant steels

How to use

Secure the drill bit in the chuck so the cylindrical shank is fully clamped and run the drill at the recommended speed for the material being machined: generally lower speeds for stainless and hard alloys, higher speeds for softer steels. Apply steady, moderate feed pressure and use cutting fluid or coolant when drilling stainless steel or heat-resistant alloys to reduce heat build-up and prolong tool life. Back off periodically to clear chips from the flutes if drilling deep holes, and avoid excessive axial force that could cause bit deflection or premature wear.

Usage recommendations

Choose drilling speeds according to material hardness and bit diameter, maintain proper coolant or cutting fluid for metal work, and replace bits showing excessive wear or chipping to preserve hole quality and operator safety.