Drill bit GRAPHITE cobalt 11 mm cylindrical for metal, model 57H058

GRAPHITE cobalt cylindrical drill bit, 11 mm diameter, designed for drilling metal. Manufactured from a cobalt-alloyed high-speed steel, this drill bit delivers improved heat resistance and greater abrasion durability compared with standard HSS bits. The cylindrical shank fits common chucks in handheld drills and drill presses, enabling straightforward use in metalworking, repair and fabrication tasks that require precise, repeatable holes in steel and other ferrous materials.

Advantages

The cobalt alloy composition increases red-hardness and maintains cutting performance at elevated temperatures, reducing wear when working with hardened steels. The cylindrical shank ensures secure holding in standard drill chucks while simplifying interchangeability. Ground cutting lips and a geometry optimised for metal produce clean holes with reduced burr formation and reliable centring during drilling.

Suitable for

• Drilling through mild and alloy steels
• Metal fabrication and sheet-metal work
• Maintenance and repair tasks on machinery and metal assemblies
• Bench drilling with drill presses and handheld drilling in metal

Key specifications

• Diameter: 11 mm
• Material: cobalt-alloyed high-speed steel (cobalt-enhanced HSS)
• Shank type: cylindrical shank for standard chucks
• Intended use: drilling in ferrous metals and hard materials
• Cutting geometry: ground for metalworking to reduce burrs and improve centring

How to use

Secure the drill bit in the chuck of a handheld drill or drill press, ensuring the cylindrical shank is clamped firmly and the bit is aligned. Select a suitable cutting speed and feed for the metal being drilled — lower speeds for hardened steels and higher speeds for softer materials — and use steady pressure without forcing the bit. Apply cutting fluid or coolant where applicable to reduce heat and extend tool life. Withdraw the bit occasionally to clear chips when drilling deep holes.

Usage recommendations

For best results, use appropriate cutting fluid and moderate speeds for hard steels; ensure the drill and workpiece are securely clamped to maintain accuracy and prolong drill bit life.