Kennametal 4109948 Threading Insert NT4L KCU25 Carbide

Product Description

The KENNAMETAL 4109948 is a carbide threading insert in the Top Notch series, designed for precision thread-cutting operations on both internal and external workpieces. Manufactured from carbide with a PVD-applied AlTiN finish, this insert handles a partial profile 60-degree thread form with a left-hand cutting orientation. It covers an external pitch range of 1.25 to 6.25 mm (4 to 20 TPI) and an internal pitch range of 2.00 to 6.25 mm (4 to 12 TPI). The NT4L insert style seats into compatible Top Notch toolholders and is suited for threading operations where tool life and coating hardness under elevated cutting temperatures are priorities.

This insert is used in CNC turning centers and manual lathes for producing left-hand threads on ferrous and non-ferrous materials. The AlTiN coating provides oxidation resistance at high cutting temperatures, making it well-suited for dry or semi-dry machining environments. Internal threading applications such as tapped bores and external applications on threaded shanks and fastener profiles are common use cases. Licensed machinists and CNC operators performing production or maintenance threading work will find this insert fits standard Top Notch toolholder systems.

Key Features

• Carbide substrate with PVD AlTiN coating for extended tool life in high-temperature cutting conditions
• Partial profile 60-degree thread form covers a wide pitch range without profile grinding per pitch
• Left-hand cutting orientation for left-hand thread applications
• Covers external pitch 1.25 to 6.25 mm (4 to 20 TPI) and internal pitch 2.00 to 6.25 mm (4 to 12 TPI)
• NT4L insert style seats in Top Notch series toolholders for repeatable indexing
• Corner radius of 0.17 mm (0.0065 inches) provides a controlled thread root form

Compatibility

Designed for use with Top Notch series toolholders accepting the NT4L insert style. Verify toolholder insert seat specifications before installation.

Installation Notes

Threading inserts must be installed by a qualified machinist or CNC operator following the toolholder manufacturer's clamping torque and seating procedures. Ensure the machine spindle is fully stopped and the toolholder is removed from the turret or tool post before indexing or replacing the insert. Inspect the insert pocket for chips or debris prior to seating the new insert, as contamination will affect insert stability and thread accuracy. Follow applicable shop safety protocols and equipment lockout procedures during any tooling changeover.