Walter 6120845 CNMG431-MK5 Turning Insert Carbide

Product Description

The WALTER 6120845 is a solid carbide turning insert in the CNMG431-MK5 WKK20S configuration, designed for precision material removal on CNC lathes and turning centers. It features a CVD-applied multilayer coating of TiCN, Al2O3, and TiCN, delivering high wear resistance and thermal stability during interrupted and continuous cuts. The insert carries an 80-degree diamond shape with a neutral hand orientation, a 0.5 inch inscribed circle, and a 1/64 inch (0.0157 inch) corner radius. The MK5 chip breaker geometry is optimized for controlled chip formation in medium to semi-finish turning passes. Licensed machinists and CNC operators in production and job-shop environments rely on this insert for repeatable, tight-tolerance results.

This insert is intended primarily for turning cast iron (ISO K20 material grade) and secondarily for steel (ISO P10 material grade). It supports multiple operations including turning, facing, and boring, making it suitable for general-purpose lathe work across both roughing transitions and finish passes. The CNMG style and 431 size code conform to ANSI and ISO standards, fitting standard CNMG toolholders with clamp and pin holding methods. The ISO designation is CNMG120404-MK5 WKK20S. It is sold individually with a minimum order quantity of 10 units.

Key Features

• CVD multilayer coating: TiCN, Al2O3, TiCN for extended tool life in cast iron and steel
• MK5 chip breaker geometry for reliable chip control in medium turning applications
• 80-degree diamond insert shape with negative rake angle for strong cutting edge
• Chamfered and honed cutting edge style reduces microchipping at entry and exit
• 4 usable cutting edges per insert maximizes cost-per-edge value
• Compatible with clamp and pin holding methods for secure seating in standard toolholders

Compatibility

Fits standard CNMG-style toolholders accepting a 431 size insert with clamp and pin holding. Conforms to ANSI and ISO CNMG120404 dimensional standards. Suited for turning, facing, and boring operations on cast iron and steel workpieces.

Installation Notes

Installation and indexing should be performed by a qualified machinist or CNC operator with the machine in a full stop and locked-out state per OSHA lockout/tagout requirements. Ensure the toolholder pocket and seating surfaces are clean and free of chips before seating the insert. Use the appropriate torque wrench and clamp hardware specified by the toolholder manufacturer - do not over-tighten the clamping screw. Inspect the cutting edge and chip breaker for damage after each index before resuming production cuts.