Walter 6120889 CNMG432-MK5 WKK20S Turning Insert

Product Description

The WALTER 6120889 is a CNMG432-MK5 WKK20S solid carbide turning insert designed for precision metal removal in industrial machining operations. Featuring a CVD-applied multilayer coating of TiCN, Al2O3, and TiCN, this insert delivers strong wear resistance and thermal stability during continuous and interrupted cuts. The 80-degree diamond shape with a negative rake angle and chamfered and honed cutting edge style provides a robust, reliable geometry suited to demanding turning cycles. With a 1/2-inch inscribed circle and a 1/32-inch corner radius, it fits standard CNMG-style toolholders and delivers consistent performance across four usable cutting edges.

This insert is primarily intended for turning cast iron and steel workpieces in production environments. Its MK5 chip breaker geometry is optimized for turning, facing, and boring operations across a range of depths of cut up to 0.1969 inches (5.00 mm). The WKK20S material grade falls within the K20 and P10 classifications, making it a practical choice for shops running medium to heavy cuts on gray cast iron or carbon and alloy steels. It is used in CNC turning centers and manual lathes wherever consistent chip control and edge life are priorities. Minimum order quantity is 10 inserts; each package contains 1 insert.

Key Features

• CVD multilayer coating: TiCN, Al2O3, and TiCN for high wear and thermal resistance
• MK5 chip breaker for controlled chip evacuation during turning, facing, and boring
• Four usable cutting edges per insert for extended tool life and lower per-edge cost
• Negative rake geometry with chamfered and honed edge for edge strength on tough materials
• Clamp and pin holding method for secure seating in CNMG-compatible toolholders
• Conforms to ANSI and ISO standards; ISO code CNMG120408-MK5 WKK20S

Compatibility

Designed for use in CNMG-style toolholders that accept a 1/2-inch inscribed circle, 3/16-inch thick diamond insert with a 0.2030-inch hole diameter. Compatible with clamp and pin holding systems. Primary workpiece material is cast iron (ISO material code K); secondary workpiece material is steel (ISO material code P). Material grades K20 and P10 apply.

Installation Notes

Turning inserts of this type are installed and indexed by qualified machinists or CNC tooling technicians. Power down and lock out the machine spindle before indexing or replacing inserts. Ensure the insert pocket and clamping surfaces are clean and free of chips before seating the insert. Use the correct torque for the clamping screw per the toolholder manufacturer specification to avoid insert movement or breakage during the cut.