CNMA120408-RK7 WKK20S Wendeplatten - Walter Tools

The reliable combination of a wear-resistant Tiger·tec Silver coating and a purpose-built RK7 chipbreaker delivers consistent tool life and process security for cast iron turning; order or request further application guidance via Metav Werkzeuge.

CNMA120408-RK7 WKK20S — Turning insert, Tiger·tec Silver, for cast iron (Walter Tools)

The CNMA120408-RK7 WKK20S is a negative-rake, rhombic turning insert engineered for productive machining of cast iron components in industrial turning applications.

• Tiger·tec Silver coating for long tool life
• Optimised RK7 chipbreaker for cast iron
• Rhombic 80° insert with 0.8 mm nose radius
• Negative 0° rake for robust turning

Consistent chip control for uninterrupted production

The combination of the RK7 chipbreaker and the Tiger·tec Silver coating is designed to provide predictable chip formation when machining abrasive cast iron grades. The chipbreaker geometry encourages short, controlled chips that evacuate reliably, reducing the risk of workpiece damage and machine downtime. As a result, the cutting process remains stable over longer tool lives, which supports higher hourly productivity and fewer tool changes — a clear economic advantage for batch production and series turning.

Built for abrasive cast iron machining with minimal compromise

The insert uses the WKK20S coated-carbide grade, developed specifically for the typical abrasive wear and brittle-chip behaviour of cast iron. This grade balances hardness and toughness so that the cutting edge resists wear while still tolerating the shock loads common in interrupted cuts. The specification explicitly lists suitability for cast iron, which means the metallurgy of the grade matches the demands of grey and nodular cast iron applications. For workshops seeking straightforward material assignment, this makes tooling selection faster and process planning more reliable.

Secure geometry and robust edge for accurate surface finishes

The rhombic 80° shape and 0.8 mm nose radius produce a favourable mix of strength and cutting definition: the geometry supports heavier cross-sections where edge robustness is required, while the nose radius contributes to a consistent surface finish without excessive cutting forces. The negative 0° rake increases edge stability under heavy cuts and ensures safe performance in interrupted turning. Tolerance class M and the standard A execution indicate consistent dimensions and interchangeability in typical toolholders, supporting setup repeatability and predictable part tolerances.

For personalised application advice or to secure Walter Tools Tiger·tec Silver inserts, contact Metav Werkzeuge for delivery options and machining recommendations — email info@metav-werkzeuge.com or call +49 2822 7131930.

Technical data

• Article number: CNMA120408-RK7-WKK20S-WALTER
• Product type: Turning insert
• Series: Tiger·tec Silver
• Grade: WKK20S

Data

• Size: 12
• Thickness: 04
• Nose radius: 0.8 mm
• Rake angle: 0° (negative)
• Shape: Rhombus 80°
• Chipbreaker: RK7
• Tolerance class: M
• Execution: A

Special features

• Coating: Tiger·tec Silver (coated carbide)
• Material suitability: cast iron
• Design: negative-rake rhombic insert
• Application focus: turning / interrupted cuts
• Durable edge for abrasive materials

FAQ

Which materials is this insert suitable for?
The CNMA120408-RK7 WKK20S from Walter Tools is specified for machining cast iron; the WKK20S grade is optimised for the abrasive wear and short-chip behaviour of cast iron alloys.

What benefit does the RK7 chipbreaker provide?
The RK7 chipbreaker promotes short, controllable chips in cast iron turning, improving chip evacuation and reducing the likelihood of surface damage or tool interference during production.

How does the Tiger·tec Silver coating affect tool life?
The Tiger·tec Silver coating enhances wear resistance and thermal stability of the insert, extending cutting edge life under high-abrasion conditions typical of cast iron machining.

Is the insert suitable for interrupted cuts or finishing operations?
With a negative 0° rake and 0.8 mm nose radius, the insert is robust for interrupted cuts and can achieve acceptable surface quality for general finishing; fine finishing may require a smaller nose radius or different grade.

What should be considered when mounting the insert?
Ensure a properly matched toolholder for rhombic 80° geometry and confirm clamping stability; the tolerance class M supports reliable seating and repeatable positioning in standard holders.

Manufacturer/Responsible: Walter Deutschland GmbH, Derendinger Straße 53, 72072 Tübingen

Walter Tools and associated brand names are protected trademarks of their respective owners. There is no affiliation between Metav Werkzeuge and the trademark holders implied by this description. The offered item is an original, factory-new product from Walter Tools.