Drill bit for metal GRAPHITE 57H034 cobalt cylindrical 5.2 mm

GRAPHITE 57H034 cobalt cylindrical drill bit with a 5.2 mm diameter is designed for drilling steel, stainless steel and other hard metal alloys. Made from cobalt-alloyed high-speed steel, the bit offers increased heat resistance and improved wear performance compared with standard HSS drills. Its cylindrical shank allows secure clamping in standard chucks of hand drills and drill presses, making it suitable for both portable and workshop use in metalworking, maintenance and fabrication tasks.

Advantages

The cobalt-alloyed cutting material retains hardness at elevated temperatures to reduce premature dulling during prolonged cutting. The 5.2 mm diameter provides a precise hole size for mechanical assemblies and clearance drilling, while the ground flutes help evacuate chips efficiently. The cylindrical shank ensures stable clamping and straightforward replacement in common chucks. Overall, the bit balances durability and dimensional accuracy for repetitive metal drilling operations.

Suitable for

• Drilling mild steel, alloy steels and stainless steel
• Workshop fabrication and metal maintenance
• Preparation of holes for bolts, rivets and threaded inserts
• Use with hand-held drills and drill presses

Key specifications

• Diameter: 5.2 mm
• Material: cobalt-alloyed high-speed steel (HSS-Co)
• Shank type: cylindrical
• Tip/point: ground for metal drilling
• Recommended use: drilling hard metals and alloys

How to use

Secure the drill bit in the drill chuck ensuring it is centered and tightened. Mark the drilling point on the workpiece and, where appropriate, use a centre punch to prevent walking. Start drilling at moderate speed, applying steady pressure; increase cutting speed carefully while monitoring heat generation. Use cutting fluid or coolant when drilling stainless steel or other heat-sensitive alloys to prolong tool life and improve chip evacuation. Retract periodically on deep holes to clear chips and allow cooling.

Usage recommendations

For optimal performance, select drill speeds lower than those used for standard HSS when working with stainless steel or hard alloys, and employ appropriate cutting fluid. Inspect the bit for wear before use and replace when cutting edges become rounded or chip evacuation degrades.