Kennametal 4121706 TNMG542MS KCU25 Carbide Turning Insert

Product Description

The KENNAMETAL 4121706 is a TNMG542MS indexable turning insert in the KCU25 grade, designed for general-purpose and demanding metal removal on CNC lathes and turning centers. The insert is manufactured from solid carbide and coated with AlTiN via a PVD process, providing moderate wear resistance and toughness across a range of workpiece materials. The triangular 60-degree geometry features a 5/8-inch inscribed circle, a 0.0313-inch corner radius, and a honed cutting edge style. With 6 usable cutting edges and neutral hand orientation, this insert offers economical tooling cost per edge in production environments. Licensed machinists and CNC operators install this insert in KENLOC-style toolholders.

This insert is suited for turning, facing, and boring operations on steel, stainless steel, cast iron, aluminum and non-ferrous materials, and superalloys including titanium. The MS chip breaker geometry is rated for roughing and medium machining applications, making it a practical choice for shops running interrupted or variable-depth cuts on P, M, K, N, and S workpiece material classifications. The negative rake and negative side clearance geometry provides added edge strength during heavier chip loads. Maximum depth of cut reaches 0.3603 inches.

Key Features

• AlTiN coating applied via PVD process for moderate wear resistance and thermal protection
• MS chip breaker designed for roughing and medium machining operations
• 6 usable cutting edges per insert for lower cost per edge
• Honed cutting edge style reduces microchipping on interrupted cuts
• Compatible with clamp and pin insert holding methods
• Neutral hand orientation fits a wide range of TNMG-style toolholders

Compatibility

Designed as an OEM-style replacement and standard drop-in for KENLOC-series and other TNMG-style toolholding systems conforming to ANSI insert code TNMG542 and ISO insert code TNMG270608. Fits toolholders that accept a triangular insert with a 0.2500-inch hole diameter and 0.2500-inch insert thickness.

Installation Notes

Installation is performed by qualified machinists or CNC tooling technicians. Power down and lock out the machine before indexing or replacing inserts. Use the appropriate torque wrench and clamp screw specified by the toolholder manufacturer when seating the insert — do not overtighten by hand estimation. Inspect the toolholder pocket for wear or debris before seating a new insert to ensure proper contact and repeatable edge location.