Drill bit for metal GRAPHITE HSS DIN 338 4 mm, 2 pcs

GRAPHITE HSS DIN 338 drill bits, diameter 4 mm, set of 2 pieces, are high-speed steel tools designed for drilling steel and other metal materials. Manufactured to DIN 338 specifications, these straight-shank, twist drills offer conventional geometry suitable for general metalworking tasks. The 4 mm diameter provides a common size for pilot holes, fastening, and precision metal fabrication, and the round-shank design is compatible with standard drill chucks used in hand drills and drill presses.

Advantages

These drill bits are made of high-speed steel (HSS), which combines hardness and toughness for reliable cutting in a wide range of ferrous and non-ferrous metals. Conformance to DIN 338 ensures consistent tip geometry and flute design for predictable chip evacuation and stable drilling performance. Supplied as a pair, the set gives immediate replacement or backup during workshop, maintenance, or on-site jobs. The straight shank and standard diameter make them versatile and easy to mount in common drilling equipment.

Suitable for

• Drilling holes in mild and medium steel
• Creating pilot holes for taps and larger drills
• Maintenance and repair work in workshops and industrial settings
• Use in hand drills and drill presses for metal fabrication

Key specifications

• Material: high-speed steel (HSS)
• Standard: DIN 338 (twist drill geometry)
• Diameter: 4 mm
• Shank type: straight/round shank for standard chucks
• Package quantity: 2 pieces

How to use

Secure the workpiece and select appropriate clamping to prevent movement during drilling. Choose proper cutting speed and feed rate for the metal being machined; reduce speed for harder or heat-sensitive alloys. Fit the 4 mm drill bit into the drill chuck and tighten securely. Apply steady, moderate pressure and allow the drill bit to cut without forcing; withdraw periodically to clear chips if drilling deep holes. Use cutting lubricant when working with steel to extend tool life and improve surface finish.

Usage recommendations

For best results, use cutting fluid when drilling steel, match drilling speed to material hardness, and inspect drill tips regularly for wear. Replace the bit if excessive wear or chipping of the cutting edges is observed to maintain hole accuracy and safety.