40mm Countersink UltimateCut 4S 90° HSS RUnaTEC Coating, 4-Flute DIN 335C - Ruko GmbH

Take advantage of the combination of high cutting performance, reduced feed force and a secure three-flat shank for continuous, reliable countersinking in steel; order the tool directly via Metav Werkzeuge or contact the consultants for application-specific advice.

Countersink ULTIMATECUT 4S — 90° HSS countersink, RUnaTEC-coated, 4-flute (RUKO)

The Countersink ULTIMATECUT 4S is a high-performance HSS countersink with a 90° geometry and four flutes, optimised for fast, low-force countersinking in steel for both stationary and manual machining.

• HSS with RUnaTEC coating for extended life
• 90° 4-flute design for fast, smooth countersinking
• Shank with three flats for secure clamping and stability

Increased throughput through lower feed force and faster cycles

The combination of HSS substrate and RUnaTEC coating delivers a countersinking tool that reduces friction and wear, enabling up to 50% faster countersinking cycles and as many as three times the number of countersinks compared with conventional tools. The 4-flute geometry and 90° cutting angle concentrate cutting action to produce a consistent chamfer while requiring less feed force, which is specified for steel up to 800 N at 0.25 mm/rev. For production environments this translates into shorter cycle times, lower spindle loads and fewer tool changes, supporting measurable efficiency gains on repetitive operations.

Stable clamping and vibration control for superior surface finish

A shank with three flats provides secure axial and rotational clamping in collets or toolholders, markedly reducing chatter and runout. The tool’s right-hand cutting design and balanced flute arrangement ensure an extremely smooth running behaviour, resulting in an optimal countersink finish without chatter marks. These characteristics make the tool suitable for delicate manual set-ups as well as rigid, high-precision machine fixtures where surface quality and repeatability are critical.

Standardised design with clear workshop benefits

Built to DIN 335 C dimensions, the countersink offers predictable interface and replacement behaviour in established tool workflows. The robust construction and coating strategy extend service life in steel applications, reducing downtime and tooling overheads. For workshop managers and production engineers, the result is a reduction in process variation and a more reliable finish at each station, whether fitting fasteners in structural assemblies or preparing components for subsequent operations.

For reliable delivery from our Emmerich warehouse and application guidance on the RUKO Countersink ULTIMATECUT 4S, contact Metav Werkzeuge by e‑mail at info@metav-werkzeuge.com or by telephone on +49 2822 7131930 to discuss suitability and availability

Technical data

• SKU: 4000605558NW
• Article label: Countersink ULTIMATECUT 4S DIN 335 C 90° Ø 40 mm HSS RUnaTEC RUKO
• Manufacturer: Ruko GmbH
• Packaging unit: 1
• UID: 4000605558NW

Core data

• Diameter: 40 mm
• Countersink angle: 90°
• Number of flutes: 4
• Feed in steel (≤ 800 N): 0.25 mm/rev
• Standard: DIN 335 C

Materials & features

• Material: HSS
• Coating: RUnaTEC
• Shank: with three clamping flats
• Cutting direction: right-hand
• Application: countersinking in steel
• Suitability: stationary and manual use
• Performance: reduced feed force, up to 3× more countersinks, up to 50% faster, quiet run, optimal finish without chatter marks

FAQ

Is this countersink suitable for use on steel?
Yes. The Countersink ULTIMATECUT 4S is designed specifically for countersinking in steel and is rated for operation up to 800 N with a recommended feed of 0.25 mm per revolution.

How does the RUnaTEC coating benefit tool life?
The RUnaTEC coating on the ULTIMATECUT reduces friction and wear under load, extending tool life and maintaining cutting performance for longer production runs.

Can the tool be used in handheld or manual setups?
Yes. The tool is optimised for both stationary and manual use; its balanced flute geometry and secure shank clamping contribute to stable, vibration-free operation in both environments.

What clamping arrangement is recommended?
A collet or holder that engages the shank with three flats is recommended to ensure positive axial and rotational location, minimising runout and chatter for consistent countersink quality.

Which standard does the tool comply with?
The design conforms to DIN 335 C, providing standardised dimensions and interchangeability for conventional countersinking applications.

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