8.3mm Countersink 90° Solid Carbide 3-Flute Blank Shank 6mm, CBN Ground Flutes - Ruko GmbH

Take advantage of razor-sharp CBN-ground flutes, a solid carbide construction and a 6 mm shank for reliable, burr-free countersinking; order directly via Metav Werkzeuge or consult our specialists for any application questions.

RUKO 90° countersink DIN 335C – 8.3 mm, solid carbide, 6 mm shank

The RUKO 90° countersink DIN 335C is a solid-carbide countersinking tool designed for burr-free countersinking, deburring and spotfacing in demanding workshop and production environments.

• CBN-ground flutes for razor-sharp edges
• 90° angle for standard countersinks
• Solid carbide for high rigidity and durability
• 3-flute geometry for smooth surface finish

Burr-free finish through precision-ground flutes

The combination of CBN-ground flutes and a precise 90° angle ensures an exceptionally sharp cutting edge that produces a consistently burr-free finish. Deep-fluted geometry evacuates chips reliably, which reduces the risk of chatter and scoring during the operation. As a consequence, rework is minimised and component quality is improved, making the tool suitable for operations where surface integrity is critical. The tool geometry is particularly effective at lower spindle speeds, where cutting forces remain controlled and tool life is extended.

Robust carbide core for repeatable results

Constructed from solid carbide (HM) and supplied uncoated (blank), the countersink combines rigidity with wear resistance for repetitive production work. The 6 mm shank fits standard collets and toolholders, enabling fast tool changes and secure clamping. The 3-flute geometry balances cutting action and chip clearance to deliver a smooth deburring process while reducing vibration. This mechanical stability yields reproducible results across batches and supports consistent cycle times on CNC machines and manual drilling rigs alike.

Process efficiency and clear machining data

Designed for countersinking, deburring and spotfacing, the tool is optimised for reliable results at low cutting speed, which is often advantageous when machining steels and mixed-material assemblies. For example, a practical feed for steel up to 500 N is 0.09 mm/rev, providing a clear starting point for process setup and minimising trial-and-error on the shop floor. Conformance to DIN 335C ensures compatibility with standard countersinking dimensions, simplifying inspection and part acceptance procedures. By delivering high initial surface quality, the tool supports downstream operations and reduces overall production costs through lower scrap and fewer touch-ups.

Contact Metav Werkzeuge in Emmerich for tailored technical advice and procurement of the RUKO countersink; reach us at info@metav-werkzeuge.com or +49 2822 7131930 to discuss integration into existing workflows

Technical Data

• Article number: 4000601474NW
• Manufacturer: Ruko GmbH
• Packaging unit: 1

Numbers

• Angle: 90°
• Diameter: 8.3 mm
• Shank diameter: 6 mm
• Flutes: 3
• Feed in steel up to 500 N: 0.09 mm/rev

Special features

• CBN deep-ground chip flutes
• Solid carbide (HM), uncoated
• For burr-free and chatter-free countersinking, deburring and spotfacing
• Optimised for low cutting speed

FAQ

Which materials is this countersink suited for?
The RUKO 90° countersink is primarily specified for steel applications and delivers best results at low cutting speeds; the documented feed in steel up to 500 N is 0.09 mm/rev.

What spindle or holder is required for this tool?
A standard 6 mm collet or holder is suitable thanks to the 6 mm shank; the solid-carbide body ensures secure clamping and repeatable concentricity.

How does the CBN grinding affect the finish?
CBN-ground flutes create extremely sharp cutting edges on the RUKO countersink, producing a clean, burr-free finish that reduces downstream rework.

Is the tool coated or uncoated?
This countersink is supplied uncoated (blank) and is engineered to perform reliably under lower cutting-speed conditions where coating benefits are less pronounced.

Which standard does the countersink comply with?
The geometry conforms to DIN 335C, making it compatible with standard countersinking dimensions and typical inspection criteria.

Ruko GmbH: Manufacturer/Responsible: Ruko GmbH Präzisionswerkzeuge, Robert‑Bosch‑Strasse 7, 71088 Holzgerlingen