Drill bit GRAPHITE cobalt for metal, cylindrical shank 4.8 mm (57H030)

GRAPHITE cobalt drill bit for metal with a cylindrical shank and 4.8 mm diameter is engineered for drilling through a range of metallic materials. The cobalt alloy composition increases hardness and heat resistance compared with standard HSS bits, making this drill suitable for prolonged cutting in tougher steels and alloys. The cylindrical shank fits standard chucks on handheld drills and drill presses where a straight shank is required.

Advantages

The cobalt material delivers improved wear resistance and retains cutting edge hardness at higher temperatures, reducing premature dulling during continuous work. The 4.8 mm cutting diameter provides accurate hole sizing for general metalworking tasks. A straight (cylindrical) shank ensures secure clamping in typical three-jaw chucks and drill press chucks. The bit’s geometry supports efficient chip evacuation and stable drilling performance in ferrous metals.

Suitable for

• Drilling holes in mild and hardened steels
• Metal fabrication and repair work
• Use with handheld drills and drill presses with cylindrical-shank compatibility
• Pilot holes and clearance holes for bolts and fasteners

Key specifications

• Material: cobalt-alloy high-speed steel
• Shank type: cylindrical (straight) shank
• Cutting diameter: 4.8 mm
• Intended use: drilling in metal (including harder steels)
• Typical mounting: compatible with standard drill chucks

How to use

Select an appropriate drilling speed for the workpiece material — lower speeds for harder steels and higher speeds for softer metals — and secure the workpiece to prevent movement. Clamp the cylindrical shank firmly in the drill chuck or press arbor. Use cutting fluid or coolant when drilling harder metals to reduce heat and prolong tool life. Apply steady pressure without forcing the bit; allow the cutting edges to remove material and clear chips periodically to avoid clogging.

Usage recommendations

For best results when drilling hardened steels, use moderate feed and reduced spindle speed with appropriate coolant. Inspect the bit for wear before extended jobs and replace when cutting performance degrades to maintain hole quality and operator safety.