Kennametal 4176025 Threading Insert 8 Tpi Acme Carbide

Product Description

The KENNAMETAL 4176025 is a carbide threading insert designed for precision thread-cutting operations on both internal and external threads. Manufactured to the NA3R8 style in the Top Notch series, it carries the KCU10 grade designation and features an AlTiN finish applied via PVD coating process. The insert produces Acme-standard threads at 8 threads per inch (TPI) with a 29-degree included angle, suited for right-hand thread cutting. The cutting tip width measures 0.0411 inches and the corner radius is 0.0050 inches, delivering tight tolerance thread geometry. Machinists and toolroom professionals install this insert in compatible Top Notch threading toolholders.

This insert is appropriate for Acme threading applications in production and jobshop environments handling right-hand internal and external thread forms. Common use cases include leadscrew, power screw, and trapezoidal thread cutting on lathes and CNC turning centers. The AlTiN PVD coating provides wear resistance suitable for a range of ferrous and non-ferrous workpiece materials. Insert size 3 fits the corresponding Top Notch holder geometry, making it a direct fit for shops already running the Top Notch platform.

Key Features

• Acme thread standard at 8 TPI with a 29-degree included angle
• Right-hand cutting orientation for standard lathe and CNC turning setups
• AlTiN finish via PVD coating process for enhanced wear resistance
• Cuts both internal and external thread forms
• Corner radius of 0.0050 inches for consistent thread root geometry
• Insert size 3, Top Notch series for direct toolholder compatibility

Compatibility

Designed for use in Top Notch series threading toolholders requiring an insert size 3, NA3R8 style. Verify holder specification before installation to confirm proper seat fit.

Installation Notes

Threading inserts should be installed by a qualified machinist or toolroom professional. Power down and lock out the machine before seating or replacing any insert. Use the manufacturer-recommended torque wrench and insert screw for the Top Notch holder to avoid seat damage — do not over-tighten by feel alone. Inspect the insert pocket and clamping screw condition before each insert change.