Sandvik Coromant 5757970 Laydown Threading Insert 32 Tpi

Product Description

The SANDVIK COROMANT 5757970 is a solid carbide laydown threading insert engineered for external UNJ thread forms at 32 threads per inch. Catalog number 266RG-16NJ01A320E 1125, this insert belongs to the CoroThread 266 series and carries a PVD-applied TiCrAlN/TiAlN dual-layer coating that resists heat and wear during continuous threading operations. The insert is right-hand oriented with a 60-degree included angle, a 3/8-inch inscribed circle, and a thickness of 5/32 inch (0.1563 inch). Grade 1125 solid carbide provides the edge stability required for consistent thread profiles on steel and alloy workpieces. Machinists and CNC tooling specialists install this insert in compatible CoroThread 266 toolholders on turning centers and CNC lathes.

This insert is suited for external UNJ threading applications on turning centers in both job-shop and production environments. The UNJ thread standard, which specifies a controlled root radius, is common in aerospace and high-strength fastener applications where fatigue resistance is critical. The single-tooth-per-side geometry and chipbreaker style A support consistent chip formation during threading passes. Installation requires a compatible CoroThread 266 insert pocket; confirm holder designation before ordering. Minimum order quantity is 10 pieces; package quantity is 1.

Key Features

• Solid carbide substrate with PVD-applied TiCrAlN/TiAlN coating for extended tool life in steel and alloy threading
• 32 TPI external UNJ thread form with 60-degree included angle
• Right-hand cutting orientation, insert style 266, size code 16
• 3/8-inch inscribed circle (9.53 mm); thickness 5/32 inch (3.97 mm)
• Chipbreaker style A for controlled chip evacuation during threading passes
• Grade 1125 carbide optimized for PVD coating adhesion and edge toughness

Compatibility

Designed for use in CoroThread 266 series toolholders that accept the 266 insert style with a 16 size code. Verify holder insert pocket geometry against catalog number 266RG-16NJ01A320E 1125 before installation.

Installation Notes

Installation is performed by machinists or CNC tooling technicians on a powered-off or e-stopped machine with all spindle motion confirmed stopped. Use the correct Torx or hex key at the manufacturer-specified seating procedure to secure the insert without over-torquing the clamping screw. Inspect the insert pocket for debris or damage before seating the new insert. Do not use damaged or chipped inserts, as edge failure during threading can damage the workpiece thread form and the toolholder pocket.