Walter 6406858 Turning Insert VNMA332-RK5 WKK20S Carbide

Product Description

The WALTER 6406858 is a solid carbide turning insert in the VNMA332-RK5 WKK20S configuration, designed for precision metal cutting in CNC turning and boring operations. It features a 35-degree diamond shape with a negative rake angle and a chamfered and honed cutting edge, providing controlled engagement and edge durability across demanding applications. The CVD multilayer coating - TiCN, Al2O3, and TiCN - delivers thermal resistance and wear protection suited for interrupted and continuous cuts. With four usable cutting edges, this insert is a cost-efficient choice for production turning environments. It is installed by CNC machinists and tooling technicians working with cast iron and steel workpieces.

This insert is engineered for turning, facing, boring, and back turning operations on cast iron (ISO material code K) and steel (ISO material code P), corresponding to material grades K20 and P10. The RK5 chip breaker geometry supports controlled chip formation across these material groups. The insert is part of the Tiger-tec Silver series and carries both ANSI and ISO standard designations. The ISO code equivalent is VNMA160408-RK5 WKK20S. Maximum depth of cut is 0.1575 inches (4.00 mm), making it appropriate for medium finishing to light roughing passes in production turning cells.

Key Features

• 35-degree diamond (VNMA) insert shape with 0.0315-inch corner radius for precise contouring
• CVD multilayer coating: TiCN / Al2O3 / TiCN for thermal and abrasion resistance
• RK5 chip breaker geometry for controlled chip flow on cast iron and steel
• Four cutting edges per insert for extended tool life per unit
• Compatible with clamp and pin holding methods
• Negative rake, zero-degree relief angle construction for rigid, stable cutting

Compatibility

Designed for use in toolholders compatible with VNMA-style inserts using clamp or pin holding methods. Primary workpiece material is cast iron (K20); secondary workpiece material is steel (P10). Multi-use application includes turning, facing, boring, and back turning. Conforms to ANSI and ISO standards for VNMA insert geometry.

Installation Notes

Installation is performed by a qualified CNC machinist or toolroom technician. The machine spindle must be fully stopped and the tool turret or holder must be locked out before inserting or indexing cutting edges. Use the appropriate torque wrench and manufacturer-specified clamping hardware for the VNMA seat to ensure proper seating - do not overtighten by feel alone. Inspect the insert pocket for wear, debris, or damage before seating a new insert.