Walter 6484653 Turning Insert DCMT21.51-MK4 WKK20S Carbide

Product Description

The WALTER 6484653 is a solid carbide turning insert designed for precision metal cutting in CNC and manual lathe applications. Designated DCMT21.51-MK4 WKK20S, this insert features a 55-degree diamond shape with a 7-degree relief angle and a positive rake geometry, producing efficient chip flow and reduced cutting forces. The CVD coating stack - TiCN / Al2O3 / TiCN - delivers heat and wear resistance appropriate for interrupted and continuous cuts. With 2 cutting edges per insert and the MK4 chip breaker geometry, it is well suited for production turning where consistency and tool life matter. Machining professionals and toolroom technicians working with cast iron or steel will find this insert a direct fit for standard DCMT-style toolholders.

This insert is rated for turning, facing, boring, and back turning operations. Its primary target material is cast iron (ISO material code K, grade K20), with steel (ISO material code P, grade P10) as the secondary workpiece material. The MK4 chip breaker is engineered to manage chip formation across light to moderate depths of cut, making this insert practical for finishing and semi-finishing passes. It meets both ANSI and ISO standards and carries the ISO designation DCMT070204-MK4 WKK20S, allowing straightforward cross-referencing in standard toolholder catalogs.

Key Features

• 55-degree diamond insert shape (shape code D) with 7-degree relief angle and positive rake for reduced cutting forces
• CVD coating process with TiCN / Al2O3 / TiCN layers under the proprietary WKK20S grade designation
• MK4 chip breaker geometry optimized for cast iron and steel at finishing to semi-finishing depths
• 2 cutting edges per insert, neutral hand, screw-held mounting via 0.1100-inch hole diameter
• Honed cutting edge style for consistent edge prep and reduced micro-chipping
• Compliant with ANSI and ISO standards; dual-coded for easy toolholder matching

Compatibility

Designed for use in DCMT-style screw-clamp toolholders that accept a 1/4-inch inscribed circle insert with a 0.1100-inch mounting hole. Compatible with turning, facing, boring, and back turning operations on cast iron (K20) and steel (P10) workpieces. ISO code DCMT070204-MK4 WKK20S and industry standard number DCMT2(1.5)1-MK4 WKK20S may be used for toolholder compatibility verification.

Installation Notes

Installation is performed by a machinist or toolroom technician using the screw-clamp method standard to DCMT insert seats. Before changing inserts, disengage the machine spindle, confirm the axis is locked, and follow the machine tool manufacturer's lockout procedure. Use the correct Torx or hex key for the insert clamping screw and do not overtighten, as solid carbide inserts are brittle and can crack under improper clamping load. Index or replace the insert at the first sign of edge wear to avoid workpiece damage or toolholder seat damage.