Kennametal 4109961 Threading Insert NTK3R KCU25 Carbide

Product Description

The KENNAMETAL 4109961 is a carbide threading insert in the Top Notch series, designed for both internal and external thread-cutting operations on CNC lathes and turning centers. Manufactured to an NTK3R insert style with a KCU25 grade, it features an AlTiN finish applied via PVD coating, which provides heat resistance and extended tool life during high-speed threading passes. The insert cuts a partial profile 60-degree thread form and is sized for a range of pitches spanning 0.60 to 2.50 mm and 10 to 44 TPI on external threads. It is a right-hand cutting insert with a corner radius of 0.08 mm and a thickness of 4.95 mm. Machinists and CNC operators in production and job-shop environments install this insert as a direct replacement or standard tooling component.

This insert covers external thread pitches from 0.60 to 2.50 mm and 10 to 44 TPI, and internal thread pitches from 1.00 to 2.50 mm and 9 to 24 TPI, making it suitable for a wide range of standard 60-degree thread forms. It is appropriate for threading operations on steel, stainless steel, and similar materials in both residential-shop and industrial production settings. The Top Notch series toolholder system accepts this insert size 3 geometry. Installation is performed by qualified machinists or CNC tooling technicians as part of routine insert indexing or replacement cycles.

Key Features

• KCU25 carbide grade with AlTiN PVD coating for extended tool life in threading applications
• Cuts both internal and external partial profile 60-degree threads in a single insert style
• External pitch range: 0.60 to 2.50 mm and 10 to 44 TPI
• Internal pitch range: 1.00 to 2.50 mm and 9 to 24 TPI
• Corner radius of 0.08 mm for precise thread form control
• Right-hand cutting orientation; compatible with Top Notch series toolholders

Compatibility

Designed for use with Top Notch series toolholding systems accepting insert size 3 geometry. Compatible with both internal and external threading applications requiring a partial profile 60-degree included angle.

Installation Notes

Installation should be performed by a qualified machinist or CNC tooling technician following the machine tool manufacturer's insert-clamping procedures. Ensure the machine spindle is at a full stop and all power is locked out before indexing or replacing inserts. Use the appropriate torx or insert-clamping wrench specified for the Top Notch toolholder to secure the insert without overtightening. Inspect the seating pocket for chips or debris before installing a new insert to maintain accurate tool geometry.