Drill bit set GRAPHITE cobalt metal, cylindrical shank 3 mm, 10 pcs (57H020-10)

GRAPHITE cobalt metal drill bits with a cylindrical shank, 3 mm diameter, set of 10 pieces. These drill bits are made from a high-speed steel base with an increased cobalt content to improve hardness, heat resistance and wear performance when working with steel and other ferrous materials. The compact set provides a consistent diameter for repeatable holes and is intended for use in handheld drills and drill presses that accept cylindrical shanks of this size.

Advantages

Cobalt alloy construction provides greater heat resistance and longer tool life when drilling hard metals compared with standard high-speed steel bits. The cylindrical shank ensures secure seating in chucks and adapters without the need for special taper mounts. A uniform 3 mm diameter across all pieces in the set simplifies tool selection for fine drilling tasks and reduces downtime due to bit changes.

Suitable for

• Drilling holes in carbon steel and alloy steel components
• Workshop and professional metalworking tasks
• Use in handheld drills and bench drill presses with cylindrical shank chucks
• Repair, maintenance and fabrication jobs that require small-diameter precision holes

Key specifications

• Material: high-speed steel with cobalt alloy
• Shank type: cylindrical
• Diameter: 3 mm
• Quantity in set: 10 pieces
• Intended use: drilling in ferrous metals

How to use

Mark the drilling position and secure the workpiece to prevent movement. Select an appropriate cutting speed and feed for the metal being drilled—slower speeds are recommended for harder steels to reduce heat buildup. Use a suitable cutting fluid or lubricant to improve chip evacuation and extend bit life. Start drilling with steady, even pressure, withdraw periodically to clear chips, and finish the hole with a controlled feed to maintain diameter accuracy.

Usage recommendations

For best results when drilling hard or thick ferrous materials, use a cutting fluid, maintain moderate speed, and avoid excessive axial force that can cause premature wear or breakage of the 3 mm bits. Inspect bits for wear and replace when cutting performance or hole quality declines.