RUKO MGB-DIN5156-HSSCo-55°-Rp-1-3/8 Countersink Bit, HSS-Co 5%, 90°, 31.0 mm, 12.0 mm Shank

Creating clean, precise countersinks for screw heads in tough materials demands a tool that stays sharp and resists heat. The RUKO MGB-DIN5156-HSSCo-55°-Rp-1-3/8 countersink bit is engineered from high-speed steel with 5% cobalt, delivering the hardness and thermal resistance needed for consistent performance in steel, cast iron, non-ferrous metals, and plastics. Its 90° cutting angle matches standard countersunk screw heads, while the three-flute design ensures smooth chip evacuation and a chatter-free finish. The cylindrical shank fits securely in both hand-held and stationary machines, making it a versatile choice for deburring, chamfering, and countersinking tasks across workshops and production lines.

Who is it for

This countersink bit is built for machinists, metalworkers, and maintenance professionals who demand reliable cutting tools for daily use. It suits anyone working with steel or cast iron components, as well as those handling non-ferrous metals or plastics in fabrication, repair, or assembly work.

Main features

• Made from HSS-Co 5% (high-speed steel with 5% cobalt) for enhanced hardness and heat resistance
• 90° cutting angle ideal for standard countersunk screws
• Three flutes for smooth cutting and efficient chip removal
• Cylindrical shank with 12.0 mm diameter for secure clamping
• Ground profile for precise cutting edges and long life
• Bright uncoated finish for reduced friction and easy inspection

Specifications

• Tool type: Countersink bit
• Material: HSS-Co 5%
• Cutting angle: 90°
• Cutting diameter: 31.0 mm
• Shank type: Cylindrical
• Shank diameter: 12.0 mm
• Overall length: 71.0 mm
• Standard: DIN 335 C
• Number of flutes: 3
• Surface finish: Bright
• Application: Deburring, chamfering, countersinking for screws
• Suitable materials: Steel, cast iron, non-ferrous metals, plastics
• Recommended use: Universal use in hand-held and stationary machines
• Manufacturing process: Ground profile
• Packaging: Single piece

Tips

For optimal results, use a cutting speed appropriate for the workpiece material and apply a suitable cutting fluid when working with steel or cast iron. Ensure the bit is securely clamped in the chuck to prevent vibration. Regularly inspect the cutting edges for wear and replace the bit when performance declines to maintain clean countersinks.