CNMG120408-MK5 WKK20S Wendeplatten - Walter Tools

Take advantage of the combination of durable Tiger·tec Silver coating, a purpose-built WKK20S grade for abrasive cast iron, and a precise MK5 chipbreaker to maintain steady production and predictable tool life; order the CNMG120408-MK5 WKK20S directly via Metav Werkzeuge or consult our application specialists for tailored recommendations.

CNMG120408-MK5 WKK20S Walter Tools – Indexable turning insert for cast iron, Tiger·tec Silver, Rhombic 80°

A high-performance indexable turning insert, the CNMG120408-MK5 WKK20S is designed for efficient machining of cast iron and delivers consistent edge life thanks to its Tiger·tec Silver technology.

• Tiger·tec Silver coating for extended edge life
• Optimised for cast iron machining
• Rhombic 80° geometry, 0° negative rake
• MK5 chipbreaker for controlled chip formation

Durable grade tailored to abrasive cast-iron work

The turning grade combines the WKK20S material technology with Tiger·tec Silver coating to resist abrasive wear typical of cast-iron machining. This combination provides a stable cutting edge that reduces flank wear and maintains dimensional consistency over longer tool cycles. The designation indicates a coated cemented carbide solution optimised for the short, brittle chips and abrasive conditions of grey and nodular cast irons; the result is fewer tool changes and improved process reliability in series production.

Geometry that balances strength and surface quality

With a rhombic 80° profile and a 0° (negative) free rake, the insert offers a robust cutting nose that handles interrupted cuts and vibrations with ease. The 0.8 mm corner radius supports a favourable edge strength for medium-duty turning without compromising surface finish. The geometric set-up, in combination with the MK5 chipbreaker, helps to direct chips reliably and to keep cutting forces predictable, which in turn contributes to steady cycle times and reduced rework.

Chip control and productivity advantages

The MK5 chipbreaker is calibrated for the brittle chips produced when machining cast iron, promoting short, controllable chips and stable evacuation. This improves workplace safety and reduces the need for manual chip clearing. The insert’s configuration supports consistent metal removal and stable cutting conditions, making it well suited to serial machining where repeatable surface quality and extended insert life are priorities.

Compatibility, handling and workshop integration

The insert is supplied in the CNMG format and matches standard CNMG pockets in turning toolholders, allowing straightforward replacement and minimal set-up time. The tolerance class M and the clear designation ensure reliable indexing and fitment across holders that accept this family. For application-specific parameters such as cutting speeds, feeds and depth of cut, or for advice on optimal holder pairings, Metav Werkzeuge’s consultants can provide targeted support to integrate the insert into established processes with minimal disruption.

Contact Metav Werkzeuge for tailored machining advice on the Walter Tools CNMG120408-MK5 WKK20S insert and to determine the best machining strategy for cast iron applications

Technical data

• Article number: CNMG120408-MK5-WKK20S-WALTER
• Product type: Indexable turning insert (Drehwendeschneidplatte)
• Manufacturer: Walter Tools
• Grade/series: WKK20S, Tiger·tec Silver
• Designation: CNMG120408-MK5 WKK20S

Core data

• Size code: 12
• Thickness code: 04
• Corner radius: 0.8 mm
• Free rake: 0° (negative)
• Shape: Rhombus 80°
• Chipbreaker: MK5
• Tolerance class: M

Special features

• Coating: Tiger·tec Silver
• Intended material group: K (cast iron)
• Series description: WKK20S is a Walter grade (coated carbide) optimised for cast iron
• Execution: G
• Material base: coated cemented carbide (Hartmetall)

FAQ

What materials is this insert designed for?
The CNMG120408-MK5 WKK20S insert is engineered primarily for cast iron (material group K) and is optimised for the abrasive, short-chip behaviour typical of these alloys.

What does the WKK20S designation indicate?
WKK20S denotes Walter’s coated carbide grade within the Tiger·tec Silver family, selected for wear resistance and versatility in cast-iron machining.

How does the MK5 chipbreaker affect performance?
The MK5 chipbreaker produces short, controllable chips in brittle materials, improving evacuation and contributing to reliable cycle times and safer handling.

Which geometry features improve tool life and stability?
The combination of the rhombic 80° form, 0° negative rake and a 0.8 mm corner radius offers a robust cutting edge that resists chipping and maintains surface quality under interrupted cuts.

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

The Walter AG (brand appearance: Walter Tools) with headquarters in Tübingen is one of the world’s leading manufacturers of precision tools for metalworking and is part of the Swedish Sandvik group. Trademarks and trade names are the property of their respective owners. Brand names and protected product designations are used only for explanatory purposes. There is no affiliation between our company and the named brands; the offered item is an original, factory-new product of the respective manufacturer.