Sandvik Coromant 5721287 Indexable Boring Bar Right Hand

Product Description

The SANDVIK COROMANT 5721287 is a steel indexable boring bar from the CoroTurn 107 series, designed for internal boring and turning operations on CNC lathes and turning centers. It features a 1/4 inch shank diameter and a 3.25 inch overall length, with a minimum bore diameter of 0.3425 inches (8.70 mm). The toolholder accepts a single TCMT 1.21.20 insert secured by screw clamping, and includes coolant-through capability to support chip evacuation and heat management during tight-bore applications. The neutral rake geometry and right-hand cut orientation make this bar suitable for a broad range of ferrous and non-ferrous materials.

This boring bar is used in precision internal machining applications where small bore diameters are required. Its compact neck diameter of 0.25 inches allows access to tight bore geometries in both roughing and finishing passes. The multi-use designation supports both boring and turning operations, making it a versatile toolholder for job shops and production machining environments. It is typically installed and operated by machinists and CNC programmers working with small-diameter internal features on turned components.

Key Features

• Minimum bore diameter of 0.3425 inches (8.70 mm) for tight internal bore applications
• Screw clamping insert retention for secure, repeatable positioning of TCMT 1.21.20 inserts
• Coolant-through design aids chip control and tool life in small-bore conditions
• Neutral rake angle (0 degrees) and 0-degree lead angle provide stable cutting geometry
• Right-hand cut orientation with 1/4 inch shank diameter for standard toolholder compatibility
• Multi-use capability supports both boring and turning operations from a single toolholder

Compatibility

Designed for use with TCMT 1.21.20 inserts. Part of the SANDVIK COROMANT CoroTurn 107 series. Compatible with toolholding systems accepting a 1/4 inch round shank.

Installation Notes

Installation should be performed by a qualified machinist following the machine tool manufacturer's setup procedures. Secure the shank fully within the toolholder bore and verify runout before cutting. Power down and lock out the machine spindle before changing inserts or adjusting the boring bar. Follow the insert manufacturer's recommended clamping torque guidelines using the appropriate Torx or hex key supplied with the toolholder system.