Sandvik Coromant 5757851 Threading Toolholder External Rh

Product Description

The SANDVIK COROMANT 5757851 is an indexable external threading toolholder from the CoroThread 266 series, designed for right-hand threading operations on CNC lathes and turning centers. The holder features a 0.75 x 0.75 inch square shank with a 4.5-inch overall length, providing rigid support during thread-cutting passes. It accepts 266RG to 16 series inserts secured by a screw-clamping method, offering repeatable insert positioning for consistent thread form. The steel shank construction handles the cutting forces typical in external threading applications. Machinists and CNC setup technicians install this holder in standard turning or threading cycles on production and job-shop lathes.

This toolholder is suited for external threading operations on both production turning centers and manual engine lathes equipped with a 0.75-inch tool post or gang-slide slot. It is part of the CoroThread 266 system, which is built around a fixed geometry insert platform. The 1.0-inch center-to-cutting-edge measurement supports standard tooling height setup on machines with centerline shim adjustments. No coolant-through capability is present, so flood or mist coolant must be directed externally at the cutting zone.

Key Features

• CoroThread 266 series platform accepts 266RG to 16 insert style for external threading
• Screw-clamp insert holding method for secure, repeatable insert seating
• 0.75 x 0.75 inch square shank fits standard lathe toolholding blocks and turrets
• 4.5-inch overall length with 1.0-inch center-to-cutting-edge dimension
• Steel shank construction for rigidity under threading load
• Right-hand cutting orientation for conventional external threading direction

Compatibility

Designed for use with 266RG to 16 series indexable threading inserts within the SANDVIK COROMANT CoroThread 266 tooling system. Fits machine tool posts and turret blocks accommodating a 0.75 x 0.75 inch square shank.

Installation Notes

Installation is performed by CNC machinists or lathe operators. Power down and lock out the machine spindle before inserting or removing the toolholder from the turret or tool post. Verify tool centerline height against the spindle centerline before initiating any threading cycle, as height offset directly affects thread form accuracy. Insert clamping screws should be tightened with the appropriate Torx or hex key driver per the insert manufacturer's torque guidance; do not overtighten, as this can damage the insert seat.