Kennametal 4109964 Threading Insert NTP3L KCU25 Carbide

Product Description

The KENNAMETAL 4109964 is a carbide threading insert designed for cutting precise thread forms on both internal and external workpieces. Manufactured to the NTP3L insert style in Kennametal's Top Notch series, it carries a KCU25 grade with a PVD-applied AlTiN finish for improved wear resistance and heat tolerance at the cutting edge. The insert produces a partial profile 60-degree thread form and is configured for left-hand threading operations. With an external pitch range of 1.25 to 4.00 mm (6 to 20 TPI) and an internal pitch range of 2.00 to 5.00 mm (5 to 12 TPI), it covers a broad range of common thread sizes. Machinists and toolroom professionals install this insert into compatible Top Notch toolholders on CNC lathes and manual turning centers.

This insert is suited for threading operations in production and job-shop turning environments where both internal and external threads are required in a single tooling setup. The left-hand orientation makes it appropriate for reverse-thread applications or left-hand spindle configurations. The AlTiN coating supports use in a wide range of workpiece materials, including steels, stainless steels, and cast irons, where elevated cutting temperatures are common. Insert size 3 fits standard Top Notch series holders designed for that size designation.

Key Features

• Carbide substrate with PVD AlTiN finish for extended tool life in demanding materials
• Partial profile 60-degree included angle for internal and external thread cutting
• Left-hand insert configuration for reverse-thread and left-hand spindle applications
• External pitch range: 1.25 to 4.00 mm (6 to 20 TPI)
• Internal pitch range: 2.00 to 5.00 mm (5 to 12 TPI)
• Top Notch series design for secure, repeatable seating in compatible toolholders

Compatibility

Designed for use with Top Notch series toolholders accepting Insert Size 3 NTP-style threading inserts. Confirm toolholder designation accepts left-hand NTP3L geometry before installation.

Installation Notes

Threading inserts of this type are installed and indexed by qualified machinists or toolroom technicians. Ensure the machine spindle is at a complete stop and all power is locked out before changing inserts. Use the appropriate torque wrench and clamping screw specified by the toolholder manufacturer — do not overtighten. Verify insert seating and clearance before resuming cutting operations.