RUKO FLS-DIN373-M-8 Kernloch Counterbore, HSS, M8, Pilot Hole

Counterboring for hexagon socket head cap screws often requires a precise pilot hole to guide the tool and achieve a clean, flat seat. The RUKO FLS-DIN373-M-8 Kernloch counterbore solves this with a pilot diameter matched to the core hole for M8 screws, ensuring accurate alignment and reduced walking during cutting.

Who is it for

Machinists and metalworkers who need to create counterbores for M8 socket head cap screws in steel, cast iron, or non-ferrous metals. It is suited for use on drilling machines and milling machines with a cylindrical shank.

Main features

• DIN 373 standard counterbore with pilot hole (Kernloch) for M8 screws
• HSS (high-speed steel) construction with bright finish
• Three flutes for efficient chip evacuation
• Cylindrical shank with h8 tolerance for secure holding
• Right-hand cutting direction

Specifications

• Standard: DIN 373
• Screw size compatibility: M8
• Counterbore diameter (d1): 15 mm
• Pilot diameter (d2): 9 mm
• Shank diameter (d3): 10 mm
• Total length (l1): 80 mm
• Cutting length (l2): 18 mm
• Material: HSS
• Number of flutes: 3
• Shank type: Cylindrical
• Cutting direction: Right-hand
• Surface finish: Bright
• Shank tolerance: h8
• Application: Counterboring for hexagon socket head cap screws (e.g., DIN 912, ISO 4762)
• Manufacturing process: Ground
• Suitable materials: Steel, cast iron, non-ferrous metals

Tips

Use appropriate cutting fluid and recommended speeds for HSS tools to extend tool life and achieve a clean finish.