RUKO FLS-DIN373 Core Hole Counterbore M16 MK3 HSS Flat Countersink

Precision-ground HSS flat countersink with a 26.0 mm cutting diameter for M16 cylinder head screws.

Overview

The RUKO FLS-DIN373 is a flat countersink conforming to DIN 373, engineered for creating flat-bottomed counterbores for hexagon socket head cap screws. It features a Morse Taper MK3 shank for secure tool holding and a pilot diameter of 17.0 mm with h8 tolerance, ensuring accurate centering in pre-drilled core holes.

What stands out

• Three-flute design for smooth cutting and efficient chip evacuation
• Bright finish reduces friction and improves chip flow
• Suitable for steel, cast iron, non-ferrous metals, and plastics
• Right-hand cutting direction for standard machining

Technical details

• Tool Type: Flat Countersink
• Standard: DIN 373
• Nominal Thread Size: M16
• Shank Type: Morse Taper MK3 (MT3)
• Material: HSS (High Speed Steel)
• Cutting Diameter (d1): 26.0 mm
• Pilot Diameter (d2): 17.0 mm
• Overall Length (l1): 160 mm
• Flute Length (l2): 40 mm
• Number of Flutes: 3
• Cutting Direction: Right-hand cutting
• Surface Treatment: Bright finish
• Application: For countersinking holes for cylinder head screws
• Suitable Materials: Steel, cast iron, non-ferrous metals, plastics
• Manufacturing Process: Ground profile
• Tolerance (Pilot Diameter): h8
• Recommended Screw Types: DIN 912, DIN 7984, DIN 6912

Our verdict

A professional-grade countersink that delivers clean, accurate counterbores for M16 fasteners in a wide range of materials.