Walter 6636303 Turning Insert VBMT331-MM4 WMP20S Carbide

Product Description

The WALTER 6636303 is a VBMT331-MM4 WMP20S solid carbide turning insert designed for precision metal removal on CNC lathes and turning centers. It carries a CVD-applied multilayer TiCN/Al2O3/TiCN coating under the WMP20S proprietary grade, delivering wear resistance and thermal stability across a broad range of cutting conditions. The 35-degree diamond shape (Insert Shape Code V) provides a sharp, acute cutting geometry suited to profiling and finishing passes. With a 3/8-inch inscribed circle, 3/16-inch thickness, and a 1/64-inch corner radius, the insert fits standard VBMT-style toolholders and offers two usable cutting edges per insert.

This insert is rated for primary use on steel (ISO P25) and stainless steel (ISO M20), with secondary capability on super-alloys and titanium (ISO S20). It is suited to turning, facing, boring, and back-turning operations in both production and job-shop environments. The MM4 chipbreaker geometry and positive rake angle of 7 degrees support controlled chip formation during moderate to light cuts, with a maximum depth of cut of 0.078 inches (2.00 mm). Screw-type insert holding keeps the insert locked securely in the pocket during interrupted or continuous cuts.

Key Features

• CVD multilayer TiCN/Al2O3/TiCN coating for elevated wear and crater resistance
• WMP20S grade rated for steel (P25), stainless steel (M20), and super-alloys/titanium (S20)
• 35-degree diamond insert shape with positive rake and honed cutting edge for reduced cutting forces
• MM4 chipbreaker geometry supports turning, facing, boring, and back-turning
• Two cutting edges per insert; screw-clamp holding method
• Complies with ANSI and ISO standards; ISO code VBMT160404-MM4 WMP20S

Compatibility

Designed for use in VBMT-style screw-clamp toolholders accepting a 3/8-inch inscribed circle insert. Compatible with turning centers and CNC lathes running steel, stainless steel, super-alloys, and titanium workpieces. Industry standard number VBMT331-MM4 WMP20S confirms fit across ANSI- and ISO-compliant toolholder systems.

Installation Notes

Installation is performed by qualified machinists or CNC tooling technicians. Ensure the machine spindle is stopped and the turret is indexed to a safe position before seating or replacing inserts. Verify the insert pocket and seating surface are clean and free of chips before tightening the clamping screw to avoid rocking or improper seating. Inspect the cutting edge condition at regular intervals and index or replace the insert before tool failure causes workpiece damage or toolholder wear.