Carmex 16ER8STACMEP25C Threading Insert 8 Tpi Stub Acme

Product Description

The CARMEX 16ER8STACMEP25C is a solid carbide laydown threading insert designed for external Stub Acme thread cutting at 8 threads per inch (TPI). It features a 29-degree included angle and a PVD-applied titanium nitride (TiN) coating for extended tool life across a wide range of workpiece materials. With a 3/8 inch inscribed circle and 0.146 inch thickness, this insert seats in standard ER-style laydown toolholders. It is intended for right-hand external threading operations on CNC lathes and turning centers operated by machinists and toolroom professionals.

This insert is suited for Stub Acme threading applications across universal workpiece material categories including steel, stainless, cast iron, non-ferrous, high-temp alloys, and hardened materials. It is appropriate for production threading in both job shop and high-volume turning environments where consistent thread form and tool change repeatability are required. The P25C grade with TiN coating positions this insert for general-purpose threading across the broadest practical range of materials.

Key Features

• Solid carbide construction, manufacturer grade P25C, material grade C5
• PVD TiN coating for wear resistance and extended insert life
• 29-degree included angle conforming to Stub Acme thread standard
• Right-hand external thread orientation, 8 TPI
• 3/8 inch (0.3750 inch) inscribed circle for ER-style laydown holders
• Universal primary workpiece material compatibility: H, K, M, N, P, S material codes

Compatibility

Designed for use in ER-style laydown threading toolholders accepting a 3/8 inch inscribed circle insert. Suitable for right-hand external Stub Acme threading operations on CNC turning equipment.

Installation Notes

This insert is installed and indexed by qualified machinists or CNC toolroom personnel. Power down and lock out the machine spindle before seating or replacing inserts. Use the appropriate torx or clamp screw driver specified by the toolholder manufacturer to secure the insert without overtightening. Verify thread form with a gauge after first-article threading to confirm correct pitch and profile before full production runs.