20.5mm Countersink UltimateCut 4-Flute HSS RUnaTEC Coated 90° Shank With 3 Flats, 0.21mm/rev Ruko GmbH

Efficient countersinking in steel is achieved by combining HSS construction with a RUNaTEC coating and a 4‑flute geometry, delivering quieter operation, significantly reduced feed force and faster cycle times. Order the tool directly via Metav Werkzeuge or consult their specialists for specification advice.

ULTIMATECUT 4S countersink — 90° HSS, RUKO, 4‑flute, Ø20.5 mm

ULTIMATECUT 4S countersink: a high-performance HSS countersink for precise 90° chamfering and deburring in steel applications

• HSS with RUNaTEC coating for long life
• 4‑flute geometry for smooth, quiet running
• 90° countersink for precise chamfering
• Up to 50% faster countersinking in steel

Faster cycle times with consistent chamfer quality

The combination of HSS substrate and a RUNaTEC coating gives the countersink a high wear resistance and thermal stability, which translates into longer tool life and stable process windows. The tool’s geometry reduces the required cutting force, so production runs benefit from reduced feed force and fewer interruptions. Where conventional countersinks slow down under load, this design enables up to 50% faster chamfering and, according to manufacturer data, allows for up to three times the number of countersinks before tool change in comparable conditions. The specified feed guidance in steel — up to 800 N with a feed of 0.21 mm per revolution — clarifies machining parameters and supports predictable cycle planning.

Easier handling for manual and stationary machining

A 4‑flute geometry ensures steady cutting engagement and a calm, low‑vibration operation that improves surface finish and reduces chatter. The shaft is supplied with three clamping flats, which secures the tool in typical collets and chucks and prevents slippage during manual operation or when used in bench and production machinery. The right‑hand cutting orientation and the optimised cutting edge layout create an optimal chamfer without ratter marks, lowering rework rates and operator fatigue in repetitive tasks. This makes the countersink equally suited to hand‑held use and fixed‑spindle setups in workshops or small series production.

Clear standards, dimensions and typical applications

Built to DIN 335 C, the tool provides a standardised 90° chamfer suitable for preparation of countersunk screw seats, precise deburring and chamfering of bore edges. The nominal diameter Ø20.5 mm and the 90° angle are ideal for common assembly preparations in steel components. The tool is optimised specifically for steel machining; the geometry and coating support higher cutting speeds and a smooth finish even when working close to tolerance limits. For planners and operators, the specification data such as material (HSS), coating (RUNaTEC), flutes (4) and the feed recommendation (0.21 mm/rev at up to 800 N) offer a practical basis for process setting and quality assurance.

Contact Metav Werkzeuge for tailored advice and reliable supply from Emmerich — email info@metav-werkzeuge.com or call +49 2822 7131930

Technical data

• Article number: 4000605554NW
• Item designation: ULTIMATECUT 4S countersink, 90° Ø20.5 mm
• Manufacturer: Ruko GmbH
• Packaging unit: 1
• UID: 4000605554NW

Core technical figures

• Diameter: 20.5 mm
• Countersink angle: 90°
• Number of flutes: 4
• Feed in steel up to 800 N: 0.21 mm/rev
• Standard: DIN 335 C
• Material: HSS

Special features

• RUNaTEC-coated
• Right‑hand cutting
• Shank with 3 clamping flats
• Quiet running and optimal chamfer without chatter marks
• Suitable for stationary and manual use
• Up to 3× more countersinks and up to 50% faster in comparable conditions

FAQ

What materials is this countersink suitable for?
The ULTIMATECUT 4S countersink is optimised for the machining of steel; the HSS substrate and RUNaTEC coating are specified to perform particularly well in steel applications.

What does the 90° angle mean for my assembly?
A 90° countersink creates a standard chamfer suitable for many countersunk screw heads and provides a reliable seat; the DIN 335 C compliance ensures consistent geometry.

Can the tool be used in handheld drilling or only in machines?
The design supports both manual and stationary use: the shank with three clamping flats secures the tool in chucks used at the bench as well as in production spindles.

What feed rate should be used for steel?
Manufacturer guidance indicates a feed of 0.21 mm per revolution at cutting forces up to 800 N; this gives a sound starting point for process setup and quality control.

What distinguishes this countersink from conventional types?
The combination of HSS material, RUNaTEC coating and a four‑flute geometry reduces required feed force, runs quieter and achieves faster countersinking with improved surface quality — characteristics highlighted for the ULTIMATECUT 4S (RUKO, SKU 4000605554NW).

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