Sandvik Coromant 5857571 Threading Insert 18 Tpi Un

Product Description

The SANDVIK COROMANT 5857571 is a laydown threading insert from the CoroThread 266 series, designed for right-hand external UN thread cutting. Manufactured from solid carbide with a PVD-applied TiCrAlN/TiN coating, this insert delivers consistent thread form geometry at 18 threads per inch with a 60-degree included angle. The 3/8-inch inscribed circle and 5/32-inch thickness place it in a widely used size class for CNC lathe threading operations. Licensed machinists, tool-and-die tradespeople, and CNC operators working in production or job-shop environments will find this insert suited to high-demand threading applications in steel and alloy workpieces.

This insert is intended for external UN thread machining on CNC turning centers and lathes where consistent thread accuracy and tool life are required. The CoroThread 266 insert style is engineered for laydown-style toolholders that accept the 266 series. With a single tooth per side and the A chipbreaker geometry, it is well suited to threading operations on medium to hard materials where chip control and surface finish at the thread flanks are priorities. Applications typically include production threading of fastener-profile threads in general metalworking environments.

Key Features

• Solid carbide substrate with PVD TiCrAlN/TiN coating for extended wear resistance in threading operations
• 18 TPI UN external thread form with 60-degree included angle for precise thread profile
• 3/8-inch (9.53 mm) inscribed circle with 5/32-inch (3.97 mm) thickness in the 266 insert style
• Right-hand cutting orientation for standard external threading setups
• A chipbreaker geometry promotes controlled chip evacuation during threading passes
• CoroThread 266 series platform for compatibility with corresponding laydown toolholders

Compatibility

Designed for use with CoroThread 266 series laydown-style toolholders that accept insert size code 16. Compatible toolholders must be configured for right-hand external threading. Refer to SANDVIK COROMANT toolholder documentation for confirmed holder-insert pairings using insert style 266.

Installation Notes

Installation should be performed by a qualified machinist or CNC operator with the machine in a fully stopped and locked-out state before changing inserts. Seat the insert firmly into the toolholder pocket and torque the clamping screw according to the toolholder manufacturer specifications. Inspect the insert seat and clamping components for debris or wear before installation. Never run a threading pass without confirming the insert is fully seated and the clamp is secure.