Drill bit GRAPHITE HSS cylindrical for metal 8.5 mm (55H030)

GRAPHITE cylindrical HSS drill bit with an 8.5 mm diameter is designed for drilling holes in metal. Made from high-speed steel, this drill bit provides the hardness and toughness required for general metalworking operations. It is suitable for use in both drill presses and handheld drills and is intended for creating precise through-holes and pilot holes in steel, cast iron and non-ferrous metals during maintenance, fabrication and repair tasks.

Advantages

The HSS material offers a balance of wear resistance and toughness that sustains cutting performance at moderate drilling speeds. The cylindrical shank ensures secure clamping in standard drill chucks and holders without requiring specialized adapters. The 8.5 mm diameter provides a commonly used size for fasteners and fittings, while the fluted geometry facilitates efficient chip evacuation and stable drilling action. The bit is produced to dimensional tolerances appropriate for routine metalworking, making it a reliable choice for repetitive drilling operations.

Suitable for

• Drilling holes in mild and stainless steel sheets and plates
• Fabrication and repair tasks on cast iron and non-ferrous metals
• Use with bench drill presses for precise hole alignment
• Handheld drilling for on-site maintenance and assembly

Key specifications

• Drill type: cylindrical straight shank twist drill for metal
• Material: high-speed steel (HSS)
• Diameter: 8.5 mm
• Shank style: cylindrical (straight) shank for standard chucks
• Application materials: steel, cast iron, non-ferrous metals
• Flute geometry: spiral flutes for chip removal

How to use

Secure the workpiece using a vise or clamps to prevent movement. Fit the drill bit into the chuck of a drill press or handheld drill, ensuring the shank is properly seated and tightened. Select an appropriate spindle speed for the metal being drilled—moderate speeds for harder steels and higher speeds for softer non-ferrous metals—using cutting fluid or lubricant to reduce heat and improve tool life. Apply steady, even feed pressure until the hole is complete, then withdraw the bit while the spindle is still turning to clear chips. Inspect the drilled hole and deburr edges as needed.

Usage recommendations

For prolonged tool life, use appropriate cutting fluid and avoid excessive feed rates or speeds that cause overheating. When drilling hardened or stainless steels, reduce speed and use light pecking cycles to clear chips and prevent work hardening. Always wear appropriate eye protection and follow workshop safety procedures when operating power tools.