Drill bit set GRAPHITE 57H089, cobalt bits 1.5–10 mm, multiple sizes, metal drilling

GRAPHITE 57H089 is a set of cobalt drill bits designed for drilling metal and other hard materials. The set includes multiple diameters from 1.5 mm to 10 mm, providing a range of sizes for precision holemaking. Cobalt alloy construction improves heat resistance and wear life compared with standard high-speed steel bits, making the set suitable for prolonged use in workshop, maintenance and construction environments where reliable performance is required.

Advantages

Cobalt composition increases cutting-edge strength and helps maintain sharpness at higher temperatures, reducing the need for frequent re-sharpening. The assortment of sizes eliminates the need to purchase individual bits for common hole diameters, improving jobsite efficiency. Spiral fluting ensures efficient chip evacuation while drilling, which aids in maintaining drilling accuracy and surface finish on metal. The bits are compatible with standard drill chucks and can be used in hand-held and bench drilling machines.

Suitable for

• Drilling holes in stainless steel and hardened steels
• Metal fabrication and repair work
• Maintenance and mechanical servicing
• Construction tasks requiring precise metal holemaking
• Workshops and toolkits where a range of sizes is needed

Key specifications

• Material: cobalt alloy for improved heat resistance
• Diameter range: 1.5 mm to 10 mm
• Design: spiral flute for efficient chip removal
• Compatibility: suitable for standard three-jaw chucks and drill presses
• Recommended use: drilling of metals and other hard materials

How to use

Select the appropriate drill bit diameter for the required hole size and secure it in the drill chuck. Where possible, mark and center-punch the drilling location to prevent bit wandering. Use moderate feed pressure and appropriate spindle speed for the material being drilled; slower speeds are generally recommended for harder metals to reduce heat buildup. Apply cutting fluid or coolant when drilling metal to extend bit life and improve chip evacuation. After use, clean chips from the flutes and store the bits dry to prevent corrosion.

Usage recommendations

For longest tool life when drilling stainless or hardened steels, use reduced speed, light to moderate feed, and a suitable cutting fluid. Replace worn bits to maintain hole quality and reduce the risk of workpiece damage.