Sandvik Coromant 5857591 Threading Insert 8 Tpi Acme Solid Carbide

Product Description

The SANDVIK COROMANT 5857591 is a solid carbide laydown threading insert engineered for right-hand internal Acme thread cutting at 8 threads per inch. Part of the CoroThread 266 series, it carries a PVD-applied TiCrAlN/TiN multilayer coating that resists heat and wear during threading operations. The insert measures 3/8 inch inscribed circle and 5/32 inch (0.1563 inch) thickness, with a 60-degree included angle and a single tooth per side. Manufacturer grade 1135 is matched to the coating for a balance of toughness and edge retention in threading applications on lathes and turning centers.

This insert is suited for internal Acme threading operations on CNC lathes and manual turning centers in job shop, production machining, and maintenance-repair environments. The Acme thread profile and 8 TPI specification make it appropriate for lead screw and power transmission thread forms commonly found in industrial and motion-control applications. Licensed machinists and CNC operators working with ferrous and non-ferrous workpieces in light-to-moderate interrupted or continuous cuts will find the 1135 grade and TiCrAlN/TiN finish suitable for the task.

Key Features

• Solid carbide substrate with PVD TiCrAlN/TiN coating for extended tool life in threading
• Right-hand internal Acme thread geometry at 8 TPI with 60-degree included angle
• 3/8 inch (9.53 mm) inscribed circle for use in CoroThread 266 compatible holders
• Chipbreaker style F for controlled chip evacuation in internal threading bores
• Manufacturer grade 1135 optimized for the PVD coating and Acme profile demands
• Single tooth per side design for precise thread form control

Compatibility

Designed for use with CoroThread 266 series toolholders accepting a 16-size insert with a 0.1732 inch (4.40 mm) hole diameter. Insert style code 266RL-16AC01F080E is the manufacturers catalog designation confirming holder and pocket fitment.

Installation Notes

Installation should be performed by a qualified machinist or CNC operator with the machine in a locked-out, zero-energy state before any insert change. Seat the insert fully into the pocket and torque the clamping screw to the toolholder manufacturers specification using a calibrated torque wrench. Inspect the pocket for chips or debris before seating to avoid insert rocking or premature edge failure. Confirm thread pitch and hand designation match the workpiece drawing before beginning a threading pass.