RUKO FLS-DIN373-M-6-fein Cylindrical Counterbore HSS-E M6

In metalworking shops and maintenance departments, technicians use the RUKO FLS-DIN373-M-6-fein counterbore to create precise recesses for M6 socket head cap screws and cylinder head screws. This cylindrical counterbore is ground from solid HSS-E cobalt steel, ensuring durability and clean cutting in steel, cast iron, non-ferrous metals, and plastics.

Key specifications

• Standard: DIN 373
• Thread size: M6
• Cutting diameter (d1): 10.0 mm
• Pilot diameter (d2): 6.6 mm
• Total length (l1): 63 mm
• Pilot length (l2): 10 mm
• Shank diameter (d3): 6.0 mm
• Number of flutes: 3
• Shank type: cylindrical
• Cutting direction: right-hand
• Surface finish: bright (uncoated)
• Suitable materials: steel, cast iron, non-ferrous metals, plastics

Why choose it

Ground from solid HSS-E with cobalt, this counterbore offers high hardness (64-67 HRC) and wear resistance for reliable performance. The pilot with h8 tolerance ensures accurate alignment in pre-drilled holes, while three flutes provide smooth cutting action.

Ideal use cases

• Counterboring holes for M6 hexagon socket head cap screws
• Preparing recesses for cylinder head screws in machine components
• Deburring and enlarging holes in steel and cast iron workpieces

Good to know

Manufactured to DIN 373, this tool is suitable for use with a drill press or milling machine. The bright finish reduces friction and aids chip evacuation.