Kennametal 4059938 Milling Insert LNEU1240R08 4 KC725M

Product Description

The KENNAMETAL 4059938 is a solid carbide milling insert carrying ANSI and ISO designation LNEU1240R08 4, grade KC725M, designed for high-performance milling in demanding metal-removal applications. The insert features a Physical Vapor Deposition (PVD) TiAlN coating, a positive rake geometry, and a honed cutting edge style that promotes clean, controlled chip formation. With 4 cutting edges and a neutral hand orientation, this single-sided rectangular insert delivers extended tool life when machining steel, stainless steel, superalloys, and titanium. It is held in the cutter body by a screw-clamping method and is intended for use by machinists and tooling specialists on CNC milling equipment.

This insert is suited for production and job-shop milling operations where consistent performance across P, M, and S material grade workpieces is required. Typical applications include face milling, shoulder milling, and general-purpose milling of ferrous and high-temperature alloys in both roughing and finishing contexts. The KC725M grade and TiAlN PVD coating are well matched to interrupted cuts and variable chip loads common in aerospace, automotive, and general manufacturing environments. The insert fits cutters in the KENNAMETAL LN series and is compatible with bodies designed for the LNEU insert series.

Key Features

• KC725M solid carbide grade with PVD TiAlN coating for wear resistance on steel, stainless steel, superalloys, and titanium
• 4 usable cutting edges per insert for improved cost-per-edge economics
• Positive rake angle with honed cutting edge style for smooth chip formation and reduced cutting forces
• 0.0315 inch corner radius for controlled edge engagement and improved surface finish
• Screw-held mounting for secure, repeatable insert seating in compatible LN-series cutter bodies
• Meets ANSI and ISO standards; designated LNEU1240R08 4 under both systems

Compatibility

Designed for use with KENNAMETAL LN-series milling cutter bodies that accept LNEU-style inserts with a 1240 insert size code. Confirm cutter body pocket dimensions and insert seating requirements before installation.

Installation Notes

Installation and insert changes should be performed by qualified machinists or tooling technicians with the spindle fully stopped and the machine locked out per applicable safety procedures. Use the correct Torx or hex key to tighten the clamping screw to the cutter body manufacturer's specified torque range — do not over-torque, as this can fracture the insert or damage the pocket seat. Inspect the cutter body pocket for chips, wear, or damage before seating a new insert. Always verify insert orientation and hand designation match the cutter body requirement before resuming operation.