Walter 6839042 DCMT11T302-FM4 WSM10S Turning Insert

Product Description

The WALTER 6839042 is a solid carbide turning insert in the DCMT-FM4 series, designated DCMT11T302-FM4 WSM10S. It features a multilayer PVD coating of TiAlN, Al2O3, and Al applied over a carbide substrate for wear resistance and heat management during high-demand cutting operations. The insert carries a 55-degree diamond (rhombic) shape with a positive rake angle of 6 degrees and a 7-degree relief angle, producing a positive cutting geometry suited to finishing passes. Corner radius measures 0.20 mm (1/128 inch). Insert length is 11.63 mm (0.458 inch) and inscribed circle diameter is 9.53 mm (0.375 inch). The FM4 chip breaker geometry is optimized for finishing operations. Screw-holding method is used for secure seating in compatible toolholders.

This insert is primarily intended for machining stainless steel and superalloys and titanium (ISO material codes M and S), with secondary application in steel (ISO code P). Typical use cases include turning, facing, boring, and back turning in CNC lathe and turning center environments. The finishing-class chip breaker and honed cutting edge make it well suited to light-to-moderate depths of cut where surface finish and dimensional control are priorities. It is used by CNC machinists and toolroom technicians in precision manufacturing, aerospace, and medical component applications.

Key Features

• PVD-coated TiAlN, Al2O3, and Al multilayer coating for heat and wear resistance
• 55-degree diamond insert shape with positive rake geometry reduces cutting forces
• FM4 finishing chip breaker optimized for tight tolerances and fine surface finish
• Honed cutting edge style extends tool life on difficult-to-machine alloys
• Two cutting edges per insert (neutral hand) for cost efficiency
• Screw-holding method ensures repeatable seating and indexing accuracy

Compatibility

Designed for use with DCMT-style screw-clamp toolholders accepting a 3/8-inch inscribed circle insert. Conforms to ANSI insert code DCMT32.50.5 and ISO insert code DCMT11T302. Compatible with toolholders specifying tolerance code M and clearance code C per ANSI and ISO standards. Material grade ratings M1, S10, and P10 define the recommended workpiece material range.

Installation Notes

Indexable turning inserts are installed and replaced by CNC machinists and toolroom technicians. Ensure the machine spindle is stopped and the turret or toolpost is in a safe, locked position before indexing or replacing the insert. Seat the insert fully against the pocket locating surfaces and torque the clamping screw to the toolholder manufacturer's specification. Inspect the insert pocket for chips or debris before seating to avoid insert rocking or premature failure.