Walter 6844638 CPGT060204-MM4 WSM20S Turning Insert

Product Description

The WALTER 6844638 is a solid carbide turning insert in the CPGT-MM4 series, designed for precision metal cutting in demanding machining environments. It carries the ISO designation CPGT060204-MM4 WSM20S and features a multilayer PVD coating of TiCN, Al2O3, and Al for extended wear resistance and thermal stability. The insert has an 80-degree diamond shape with a positive rake angle of 7 degrees and a honed cutting edge, providing a clean, controlled cut on difficult workpiece materials. With 2 cutting edges and a 0.4 mm corner radius, it is suited for light to medium turning, facing, and boring passes where edge integrity and surface finish are priorities.

This insert is intended for use on CNC turning centers and manual lathes handling stainless steel, superalloys, and titanium as primary workpiece materials, with steel as a secondary application. The MM4 chip breaker geometry is optimized for these material groups, supporting stable chip evacuation during finishing and semi-finishing operations. It is installed using a screw-clamp holding method and is appropriate for shops running material grades M20, S20, and P20. Machining professionals in aerospace, medical, and industrial component production will encounter this insert in applications where tool life consistency on hard-to-machine alloys is critical.

Key Features

• PVD multilayer coating (TiCN, Al2O3, Al) under grade WSM20S for thermal and abrasion resistance
• 80-degree diamond insert shape with positive rake for reduced cutting forces on stainless and titanium
• MM4 chip breaker geometry engineered for stainless steel, superalloys, and titanium
• Honed cutting edge style for improved edge stability on difficult materials
• 2 usable cutting edges per insert; screw-clamp mounting for secure seating
• Neutral hand orientation; suitable for turning, facing, and boring operations

Compatibility

Designed for use in CPGT-style screw-clamp toolholders conforming to ANSI and ISO standards. Compatible with applications targeting material grade classifications M20 (stainless steel), S20 (superalloys and titanium), and P20 (steel). Industry standard number CPGT2(1.5)1-MM4 WSM20S.

Installation Notes

Installation is performed by a qualified machinist or tooling technician. Power down and de-energize the machine spindle before indexing or replacing inserts. Use the appropriate torx or hex key to torque the clamp screw to the toolholder manufacturer specification - do not overtighten, as this can fracture the carbide insert. Inspect the insert seat and clamp for chips or debris before seating a new insert.