Kennametal 4050057 CNMG432RP KCU25 Carbide Turning Insert

Product Description

The KENNAMETAL 4050057 is a CNMG432RP KCU25 grade carbide turning insert designed for external turning, facing, and boring operations on CNC lathes and turning centers. It features an 80-degree diamond (rhombic) insert shape, a 0.5-inch inscribed circle, and a 1/32-inch corner radius. The AlTiN coating is applied via PVD process, delivering moderate wear resistance and toughness across a broad range of workpiece materials. The negative rake and negative side clearance geometry provide strong edge support for interrupted cuts and variable stock conditions common in roughing and medium machining passes. The KENLOC series design accommodates clamp and pin holding methods.

This insert is suited for roughing and medium machining operations on steel, stainless steel, cast iron, aluminum and non-ferrous metals, and superalloys including titanium. It carries ISO material grade codes P, M, K, N, and S, making it a multi-material option where one grade needs to handle varied job shop or production turning applications. Its four cutting edges reduce per-edge tooling cost on high-volume runs. Typical users include CNC machinists and toolroom operators working on lathes with CNMG-compatible toolholders.

Key Features

• KCU25 grade with AlTiN PVD coating for moderate wear resistance and toughness across steel, stainless, cast iron, aluminum, and superalloy workpieces
• 80-degree diamond insert shape (CNMG) with negative rake and negative side clearance for robust edge stability
• Four usable cutting edges per insert
• RP chip breaker geometry optimized for roughing and medium machining
• Compatible with clamp and pin insert holding methods
• Multi-use application: turning, facing, and boring in a single insert geometry
• Meets ANSI and ISO standards; ANSI code CNMG432, ISO code CNMG120408

Compatibility

Designed as an OEM-style replacement for CNMG432RP geometry inserts in CNMG-compatible toolholders. Conforms to ANSI insert code CNMG432 and ISO insert code CNMG120408RP, making it a direct fit in any toolholder specifying that geometry and seating style.

Installation Notes

Installation is performed by a qualified CNC machinist or toolroom technician. Power down and lock out the machine spindle before indexing or replacing inserts. Use the appropriate torque wrench and clamping hardware specified by the toolholder manufacturer — do not over-tighten the clamp screw, as this can fracture the insert or damage the toolholder seat. Inspect the insert pocket and seating surface for chips or debris before installing a fresh cutting edge.