Kennametal 4121708 VNGG3305FS KCU25 Carbide Turning Insert

Product Description

The KENNAMETAL 4121708 is a solid carbide turning insert in the VNGG3305FS geometry, graded KCU25 and coated with AlTiN via a PVD process. It carries a 35-degree diamond (rhombic) shape with a neutral hand orientation and a negative rake and side clearance configuration. The inscribed circle measures 0.375 inches, the corner radius is 0.0079 inches, and insert thickness is 0.1875 inches. Designed for finishing operations, the FS chip breaker and honed cutting edge style deliver controlled chip flow and surface finish on steel, stainless steel, cast iron, aluminum, and superalloys including titanium. The insert provides four usable cutting edges and is part of the KENLOC series. Licensed machinists and CNC operators install this insert in production and job-shop turning applications.

This insert is suited for external and internal turning operations including facing, boring, back turning, and back boring. The KCU25 grade is rated for moderate wear resistance and toughness across steel (P), stainless steel (M), cast iron (K), aluminum and non-ferrous materials (N), and superalloys and titanium (S). Its PVD AlTiN coating supports elevated cutting temperatures and extends tool life in interrupted and continuous cuts. Typical applications include finishing passes on ferrous and non-ferrous components in both manual and CNC lathe setups.

Key Features

• VNGG3305FS geometry with 35-degree diamond insert shape for precise finishing cuts
• KCU25 grade with PVD AlTiN coating for moderate wear resistance and toughness
• Four usable cutting edges per insert for extended tool economy
• FS chip breaker designed for finishing operations with honed cutting edge style
• Compatible with clamp and pin holding methods for flexible toolholder fitment
• Multi-use application: turning, facing, boring, back turning, and back boring

Compatibility

Designed for use in KENLOC series toolholders accepting VNGG-style inserts with clamp or pin holding. Conforms to ANSI insert code VNGG3305 and ISO insert code VNGG160402FS. Compatible toolholders must accommodate a negative side clearance, neutral hand insert.

Installation Notes

Installation is performed by qualified machinists on CNC or manual lathes. Ensure the machine spindle is fully stopped and the toolholder is secured before seating or replacing the insert. Verify the seating pocket is clean and free of chips before clamping to maintain insert stability and dimensional accuracy. Follow the toolholder manufacturer torque guidelines for clamping screws and pins; do not over-torque, as this can fracture the carbide substrate.