Sandvik Coromant 5857557 Threading Insert 14 Tpi Npt

Product Description

The SANDVIK COROMANT 5857557 is a solid carbide laydown threading insert designed for cutting external NPT threads. It carries the CoroThread 266 series designation and is manufactured to grade 1135 with a PVD-applied TiCrAlN/TiN dual-layer coating for wear resistance and extended tool life. The insert produces a 60-degree included angle at 14 threads per inch and is oriented for right-hand cutting. It measures 3/8 inches inscribed circle diameter and 5/32 inches thick. Machinists and tool crib operators in metalworking, industrial maintenance, and pipe-fitting production environments specify this insert for precision NPT thread forms on external workpiece surfaces.

This insert is suited for external NPT threading operations on lathes and turning centers equipped with CoroThread 266-compatible toolholders. Typical applications include producing tapered pipe threads on ferrous and non-ferrous workpieces in industrial manufacturing, oil and gas component production, and mechanical assembly shops. The F chipbreaker geometry is specified for controlled chip evacuation during threading passes. Right-hand orientation means the insert advances from right to left across the workpiece in standard lathe configuration. Sold individually, with a minimum order quantity of 10 units per purchase.

Key Features

• Solid carbide substrate with PVD TiCrAlN/TiN coating for thermal and abrasion resistance
• CoroThread 266 series, grade 1135 — optimized for NPT external thread forms
• 14 TPI at 60-degree included angle for standard NPT thread profile
• F chipbreaker geometry for controlled chip flow during threading passes
• Right-hand cutting orientation for standard lathe thread-turning direction
• 3/8 inches (9.53 mm) inscribed circle diameter; 0.1563 inches (3.97 mm) thickness

Compatibility

Designed for use in CoroThread 266-series toolholders that accept a 16-size insert with a 0.1732-inch (4.40 mm) mounting hole diameter. Compatible holders must be configured for external right-hand NPT threading. Verify toolholder insert seat geometry against the manufacturers catalog number 266RG-16NT01F140E 1135 before ordering.

Installation Notes

Insert seating and clamping should be performed by a qualified machinist following the toolholder manufacturer's torque and clamping specifications for CoroThread 266-series seats. Power down and lock out the machine spindle before indexing or replacing inserts. Inspect the insert pocket and clamping screw for debris or damage before seating a new insert. Handle solid carbide inserts carefully to avoid chipping the cutting edge prior to use.