Kennametal 4050535 NPR131 KCU25 Carbide Profiling Insert

Product Description

The KENNAMETAL 4050535 is a solid carbide profiling and turning insert in the Top Notch series, grade KCU25 with an AlTiN PVD coating. It features a parallelogram shape (NPR131 style) with a negative rake angle of 10 degrees and four cutting edges, making it suitable for high-productivity turning operations. The insert measures 0.499 inches in length, 0.1875 inches thick, and carries a 0.0156-inch corner radius. With a maximum depth of cut of 0.1663 inches and a 55-degree included angle, this insert is engineered for profiling passes where edge geometry and workpiece finish matter. It is screw-held and right-hand oriented. Installation requires compatible Top Notch toolholders designed for NPR-style inserts.

This insert is suited for both roughing profiles and finish turning across a wide range of workpiece materials. Primary workpiece materials include steel, stainless steel, cast iron, non-ferrous metals, and superalloys including titanium (ISO material codes P, M, K, N, and S). Typical applications include CNC turning centers and manual lathes in job shop, production machining, and maintenance environments where consistent edge performance and extended tool life are required. The KCU25 carbide grade with fine grain substrate and PVD AlTiN coating is well matched to demanding interrupted cuts and varying material hardness.

Key Features

• Solid carbide fine grain substrate, grade KCU25 with PVD AlTiN coating for wear resistance
• Four cutting edges per insert for extended tool life and reduced per-edge cost
• Parallelogram (NPR131) shape with 55-degree included angle optimized for profiling
• Negative rake geometry with 0-degree relief angle and common chipbreaker
• Screw-held, right-hand orientation for secure clamping in Top Notch toolholders
• Compatible with ISO designation KNGX150404R20 and NPR131F standard

Compatibility

Designed for use with Top Notch series screw-clamping toolholders accepting NPR131-style inserts. ISO equivalent designation is KNGX150404R20. Also referenced under manufacturer number NPR131F.

Installation Notes

Installation should be performed by a qualified machinist or tooling technician. Ensure the machine spindle is fully stopped and the toolholder is secure in the turret before changing inserts. Use the manufacturer-specified torque wrench for the clamping screw to avoid insert cracking or seat damage. Verify insert seating and orientation before returning the machine to operation.