Twist Drill Bits Set Bosch 2607017047 HSS Cobalt 19 Pieces

The Bosch HSS Twist Drill Bits Set 2607017047 HSS Cobalt 19 Pieces provides a selection of precision ground cobalt twist drill bits engineered for reliable performance when drilling steel and other hard materials. Each bit is produced from high-speed steel with 5% cobalt alloy and fully ground flutes to improve surface quality, wear resistance and heat protection. The set is suitable for use in drill stands and drill drivers and follows DIN 338 dimensions, ensuring consistent diameter tolerance and compatibility with standard chucks.

Advantages

These HSS cobalt bits combine a 5% cobalt content and fully ground construction to extend tool life and maintain cutting efficiency under elevated temperatures. The bits feature two cutters and two flutes for fast chip evacuation and reduced clogging. A 135° split-point tip with Type N flute geometry delivers accurate centring and minimizes wandering at the start of drilling, improving precision on stainless and alloyed steels. Cylindrical shanks match the drill diameter for secure clamping in standard chucks.

Suitable for

• Drilling stainless steel and acid- or heat-resistant steels
• Drilling alloyed and non-alloyed steels
• Working with cast iron and cast steel
• Use in drill presses and hand-held drill drivers
• Professional metalworking and demanding DIY metal projects

Key specifications

• Material: High-speed steel (HSS) with 5% cobalt alloy
• Number of pieces: 19
• Tip angle: 135° split-point
• Flute type: Two-flute, Type N geometry
• Shank: Cylindrical, diameter equals drill bit diameter
• Manufacturing standard: DIN 338
• Diameter tolerance: h8

How to use

Select the correct drill bit diameter for the hole required and secure it in the chuck of a drill press or hand-held driver, ensuring the cylindrical shank is clamped firmly. Use appropriate cutting speed and feed for the material being drilled—lower speeds and steady pressure are recommended for stainless and heat-resistant steels. Apply cutting fluid or lubricant when drilling hard or heat-sensitive materials to reduce temperature and prolong bit life. Retract the bit periodically on deep holes to clear chips from the flutes.

Usage recommendations

For best results when drilling stainless or high-alloy steels, use a steady low-to-medium spindle speed, apply a suitable cutting lubricant, and allow the drill bit to cool between continuous drilling operations. Avoid excessive feed pressure to prevent premature wear or breakage.