Drill bit set Bosch HSS Twist Drill Bits Cobalt Sets

The Bosch HSS Twist Drill Bit Cobalt set delivers durable performance for drilling stainless steel and a range of other metals. Each bit is made from fully ground high-speed steel with a 5% cobalt alloy content to improve wear resistance, heat protection and surface quality. The bits feature two cutters and two flutes for efficient chip evacuation and reduced wear, and they conform to DIN 338 as Type N with a 135° split-point tip and h8 diameter tolerance. Shanks are cylindrical (equal to drill diameter) and the bits are suitable for use in drill stands and drill drivers.

Advantages

Cobalt-alloyed HSS (5%) increases tool life and heat resistance while fully ground flutes and two cutting edges improve surface finish and cutting stability. The 135° split-point tip provides accurate centring and prevents wandering at the start of drilling. Two flutes enable fast chip removal, which helps maintain cutting performance over extended use. Compliance with DIN 338 and h8 diameter tolerance ensures consistent dimensions and interchangeability.

Suitable for

• Alloyed and non-alloyed steel
• Stainless steel
• Cast iron and cast steel
• Acid- and heat-resistant steels
• Use in drill stands and hand drill drivers

Key specifications

• Brand: Bosch
• Material: Fully ground HSS with 5% cobalt
• Standard: DIN 338, Type N (flute angle)
• Tip: 135° split-point
• Shank: Cylindrical (shank diameter = drill diameter)
• Diameter tolerance: h8
• Set sizes: 1.0 mm to 8.5 mm (25-piece set)
• MPN: 2608587018
• EAN: 3165140689823

How to use

Select a drill bit size appropriate for the required hole diameter and material. Secure the workpiece and mount the cylindrical shank into the chuck of a drill stand or drill driver. Use an appropriate cutting speed and feed for the material being drilled; reduce speed and apply cutting fluid when drilling stainless or acid-resistant steels to control heat. Start drilling with steady pressure— the 135° split-point tip aids centring— and clear chips regularly to prevent clogging of the flutes.

Recommendations

For longer tool life and improved hole quality in stainless and alloy steels, use cutting fluid, moderate feed rates and avoid excessive speeds. Replace bits showing significant wear or loss of tip geometry to maintain drilling accuracy.