RUKO DIN 373 Countersink Bit M22 with Morse Taper 3 Shank, HSS, 42 mm Head Diameter, 160 mm Length

The RUKO FLS-DIN373-Kernloch-M-22-MK3 is a countersink bit engineered for counterboring holes to accommodate hexagon socket head and hexagon head screws. Unlike standard countersinks that only create a conical recess, this tool produces a flat-bottomed counterbore with a fixed pilot, ensuring precise alignment with the pre-drilled core hole. The Morse Taper 3 shank provides a secure, self-locking fit in machine spindles, making it ideal for production environments where repeatability and rigidity are critical.

Highlights

• Conforms to DIN 373 standard for counterbores with fixed pilot
• Intended for M22 thread size, with 42 mm head diameter and 22 mm pilot diameter
• Morse Taper 3 (MK3) shank for direct mounting in drilling machines, milling machines, and lathes
• Made from High-Speed Steel (HSS) with bright, uncoated finish
• Three flutes and right-hand cutting direction for efficient chip evacuation
• Ground profile for precise cutting edges and smooth operation

In daily use

This countersink is suitable for counterboring in steel, cast iron, non-ferrous metals, and plastics. The fixed pilot guides the tool into the existing hole, preventing wandering and ensuring the counterbore is concentric with the thread. Coolant is recommended to extend tool life and improve surface finish. The Morse Taper 3 shank allows quick tool changes and reliable torque transmission in industrial machines.

Full specifications

• Standard: DIN 373
• Tool type: Countersink (Flachsenker)
• Intended thread size: M22
• Shank type: Morse Taper 3 (MK3)
• Material: High-Speed Steel (HSS)
• Cutting direction: Right-hand
• Number of flutes: 3
• Head diameter (D1): 42 mm
• Pilot diameter (D2): 22 mm
• Overall length (L1): 160 mm
• Surface finish: Bright (uncoated)
• Application: Counterboring for hexagon socket head screws and hexagon head screws
• Suitable materials: Steel, cast iron, non-ferrous metals, plastics
• Manufacturing process: Ground profile
• Mounting compatibility: Drilling machines, milling machines, lathes with MK3 taper holders
• Pilot design: Fixed pilot
• Coolant recommendation: Recommended for optimal performance and tool life
• Product series: RUKO DIN 373

Final note

Engineered for precision counterboring in demanding industrial applications, the RUKO DIN 373 countersink delivers consistent results with its fixed pilot and robust HSS construction.