Drill bit set GRAPHITE cobalt metal cylindrical 3.5 mm, 10 pcs (57H023-10)

GRAPHITE cobalt metal drill bit set with cylindrical shanks, 3.5 mm diameter, 10 pieces. These drill bits are made from a cobalt-containing high-speed steel alloy designed for drilling steel and other hard metals. The 3.5 mm size provides precise small-diameter holes while the cylindrical shank suits both handheld drills and drill presses commonly used in metalworking, maintenance and repair tasks.

Advantages

The cobalt alloy formulation increases heat resistance and wear life compared with standard high-speed steel, allowing sustained cutting at higher temperatures and under heavier loads. Cylindrical shanks provide stable clamping in standard chucks and enable quick bit changes. A consistent 3.5 mm diameter across the set ensures uniform hole size, and the set of 10 pieces supports repetitive drilling without frequent regrinding or replacement.

Suitable for

• Drilling steel and stainless steel
• Creating precise small holes in hard metals
• Use with handheld electric drills and drill presses
• Maintenance, repair and metal fabrication tasks
• Workshop and professional trade applications

Key specifications

• Material: cobalt-alloy high-speed steel
• Shank type: cylindrical
• Drill diameter: 3.5 mm
• Quantity: 10 pieces
• Intended use: drilling hard metals including steel

How to use

Select an appropriate cutting speed for the material you are drilling and secure the workpiece to prevent movement. Fit a 3.5 mm cobalt bit into the drill chuck and tighten firmly. For best results on steel and other hard metals, use cutting fluid or lubricant to reduce heat and improve chip evacuation. Apply steady, moderate feed pressure; avoid excessive force that can cause bit breakage. Retract the bit periodically for chip clearance on deep holes, and allow the bit to cool if it becomes overheated.

Usage recommendations

Use a variable-speed drill or drill press and select a lower RPM for larger-diameter or harder materials. Employ cutting fluid when drilling stainless steel or other heat-sensitive alloys. Store bits in a dry, organized case to protect cutting edges and maintain consistent performance.