Carmex 16IR8STACMEP25C Threading Insert 8 Tpi Stub Acme

Product Description

The CARMEX 16IR8STACMEP25C is a solid carbide laydown threading insert designed for cutting internal Stub Acme threads at 8 threads per inch (TPI). Built to manufacturer grade P25C and material grade C5, this insert features a PVD-applied titanium nitride (TiN) coating for extended wear resistance across a broad range of workpiece materials. The 29-degree included angle is specific to the Stub Acme thread form, and the right-hand configuration suits standard internal threading operations. With a 3/8 inch (0.3750 inch) inscribed circle and a thickness of 0.146 inches, this insert fits compatible laydown-style boring and threading toolholders used in CNC turning and thread milling applications.

This insert is intended for internal Stub Acme threading on CNC lathes and turning centers. The Stub Acme thread standard is common in power transmission components, lead screws, and linear actuator assemblies where a lower-profile thread form is required compared to a full Acme. The P25C grade with TiN PVD coating is rated for universal application across steel, stainless, cast iron, non-ferrous, and high-temp alloy workpieces, making it a practical general-purpose choice for production shops and job shops running varied materials. Minimum order quantity is 10 pieces; package quantity is 1.

Key Features

• Solid carbide construction at manufacturer grade P25C (material grade C5) for rigidity and edge retention
• PVD-applied TiN coating extends tool life on a wide range of workpiece materials
• 29-degree included angle matches Stub Acme thread form geometry
• Right-hand internal threading configuration for standard bore applications
• 3/8 inch inscribed circle (0.3750 inches) and 0.146 inch thickness for compatibility with 16IR-series toolholders
• Certified to CE, ISO 13485:2016, ISO 14001:2015, and ISO 45001 standards

Compatibility

Designed for use in 16IR-series laydown threading toolholders. Compatible with workpiece materials coded H, K, M, N, P, and S per ISO material classification, covering steel, stainless steel, cast iron, non-ferrous metals, high-temperature alloys, and hardened materials.

Installation Notes

Installation is performed by a CNC machinist or toolroom technician on a lathe or turning center. Power down and lock out the machine spindle before seating or replacing the insert. Ensure the toolholder pocket and clamping screw are clean and free of chips before indexing or installing a new insert. Follow the toolholder manufacturer's clamping torque specifications and verify thread-form geometry with a thread gauge before committing to a production run.