Sandvik Coromant 5757939 Threading Insert 16 Tpi

Product Description

The SANDVIK COROMANT 5757939 is a solid carbide laydown threading insert designed for external UN thread forms at 16 threads per inch. Part of the CoroThread 266 series, it features a TiCrAlN/TiAlN PVD coating that supports cutting performance in a range of workpiece materials. The insert has a 3/8 inch (9.53 mm) inscribed circle, a thickness of 5/32 inch (0.1563 inch decimal), and a 60-degree included angle. Right-hand cutting orientation makes it suitable for standard external threading operations on CNC lathes and turning centers. It is sold individually and requires a minimum order of 10 units.

This insert is used in turning and threading applications where consistent UN thread profiles are required on external diameters. The CoroThread 266 platform is designed for rigid insert seating and repeatable thread form accuracy, making it a common choice in production machining environments. Machinists working in job shops, aerospace, and general manufacturing will find this insert appropriate for high-volume external threading passes where coating durability and edge consistency are priorities.

Key Features

• Solid carbide substrate with TiCrAlN/TiAlN PVD dual-layer coating for extended tool life
• 16 TPI external UN thread form with 60-degree included angle
• Right-hand cutting orientation for standard external threading
• CoroThread 266 series insert style for secure seating in compatible toolholders
• 3/8 inch inscribed circle with 5/32 inch thickness for precise fitment
• Chipbreaker style A suited for controlled chip formation during threading passes

Compatibility

Designed for use with SANDVIK COROMANT CoroThread 266 series toolholders that accept the 266 insert style with a 16 size code. Refer to the manufacturer catalog number 266RG-16UN01A160M 1125 when cross-referencing compatible boring bars and toolholder bodies.

Installation Notes

Installation should be performed by a qualified machinist following the toolholder manufacturer torque and clamping guidelines for the CoroThread 266 system. Ensure the machine spindle is fully stopped and the toolholder is clean and free of debris before seating the insert. Verify insert orientation matches the programmed cutting direction before commencing threading cycles. Inspect the insert seating pocket for wear or damage that could affect thread form accuracy.