Drill bit GRAPHITE model 57H023 cobalt for metal, cylindrical shank, 3.5 mm

GRAPHITE 57H023 cobalt drill bit for metal, 3.5 mm, features a cylindrical shank and is specifically engineered for drilling hardened steels, stainless steel and other metal alloys. The tool is made from high-cobalt alloy to provide increased hardness, wear resistance and improved performance at elevated cutting temperatures compared with standard high-speed steel bits. Its 3.5 mm diameter and straight shank make it compatible with common hand drills and drill presses used in workshops, maintenance and light fabrication.

Advantages

The cobalt composition improves heat resistance and retains cutting edge hardness under heavy loads, reducing the risk of premature wear. The cylindrical shank ensures secure clamping in standard chucks and enables easy replacement. Precision ground flutes provide effective chip evacuation and consistent drilling performance in tough materials. Overall, the bit combines durability and dimensional accuracy for repetitive metalworking tasks.

Suitable for

• Drilling holes in hardened steel and stainless steel
• General metal fabrication and maintenance work
• Use with hand drills and drill presses
• Piercing thin to moderately thick metal sheets and components

Key specifications

• Material: high-cobalt alloy (cobalt-enhanced high-speed steel)
• Diameter: 3.5 mm
• Shank type: cylindrical (straight) shank for standard chucks
• Tip/geometry: precision ground for metal drilling (split or standard point depending on batch)
• Application: hardened steels, stainless steels and other ferrous and some non-ferrous metals

How to use

Secure the drill bit in the chuck of a hand drill or a drill press, ensuring the shank is fully seated and tightened. Select an appropriate cutting speed and feed for the material being drilled—lower speeds for hardened and stainless steels to avoid overheating. Use cutting fluid or lubricant during drilling to improve heat dissipation and prolong tool life. Apply steady pressure without forcing the bit; allow the tool to cut and evacuate chips regularly to prevent clogging.

Usage recommendations

For best results when drilling hardened or stainless steels, use a moderate drilling speed, a quality cutting fluid, and withdraw the bit periodically to clear chips and allow cooling. Replace the bit if you notice significant dulling or chipping to maintain hole quality and operator safety.