Sandvik Coromant 5757790 Threading Insert 18 Tpi Solid Carbide

Product Description

The SANDVIK COROMANT 5757790 is a laydown threading insert designed for cutting left-hand internal UN threads. Built from solid carbide and finished with a PVD-applied TiCrAlN/TiAlN dual-layer coating, this insert delivers wear resistance and heat performance in demanding threading operations. It carries manufacturer grade 1125 and belongs to the CoroThread 266 series, which is engineered for precision single-point threading on CNC lathes and turning centers. The insert produces a 60-degree included angle at 18 threads per inch and is sized at a 3/8-inch inscribed circle with a thickness of 5/32 inches. It is installed by machinists and CNC operators working in metal fabrication, job shops, and precision manufacturing environments.

This insert is suited for internal left-hand UN thread applications on lathes and turning centers where consistent thread form and tool life are priorities. The CoroThread 266 platform is commonly used in production threading of ferrous and non-ferrous workpieces. With a single tooth per side and A-style chipbreaker geometry, it is appropriate for finishing and semi-finishing passes on through-bored and blind-hole threading operations. Sold individually, with a minimum order quantity of 10 units per order.

Key Features

• Solid carbide substrate with PVD TiCrAlN/TiAlN coating for extended tool life
• Left-hand internal UN thread form at 18 TPI with 60-degree included angle
• 3/8-inch (9.53 mm) inscribed circle, 5/32-inch (3.97 mm) thickness
• A-style chipbreaker geometry for controlled chip evacuation
• CoroThread 266 series insert with style code 266, size code 16
• Hole diameter of 0.1732 inches (4.40 mm) for secure toolholder seating

Compatibility

Designed for use in CoroThread 266 series toolholders that accept insert style 266, size code 16. Refer to the manufacturer catalog number 266LL-16UN01A180M 1125 when cross-referencing with SANDVIK COROMANT toolholder documentation.

Installation Notes

Installation is performed by qualified machinists or CNC tooling technicians. Power down and lock out the machine before changing inserts. Use the correct torx or clamping screw torque as specified by the toolholder manufacturer documentation — do not over-tighten the clamp screw, as carbide inserts are brittle and susceptible to fracture under uneven clamping force. Verify insert seating and clamp contact before resuming cutting operations.