Sandvik Coromant 5961387 Internal Threading Toolholder

Product Description

The SANDVIK COROMANT 5961387 is an indexable internal threading toolholder designed for precision thread-cutting operations on CNC lathes and turning centers. Part of the CoroThread 266 series, it features a right-hand orientation and a square 15.88 mm shank. The toolholder accepts 3/8-inch inscribed-circle inserts secured by a screw-clamp holding method, delivering reliable insert retention under threading loads. Coolant-through capability supports chip evacuation and tool life in demanding bore threading applications. The 266.RL toolholder style is built from steel for rigidity in tight-bore environments. Licensed machinists and CNC operators install this holder in production and job-shop settings.

This toolholder is suited for internal threading and grooving in bores with a minimum diameter of 20 mm (0.7874 inches). The overall length is 8 inches with a shank length of 6.937 inches and a head length of 1.063 inches. It handles a pitch range of 64 to 8 TPI, making it applicable across a broad range of unified and metric thread forms. The center-to-cutting-edge dimension is 12 mm (0.4724 inches) and the neck diameter is 0.625 inches. It is rated as a multi-use tool compatible with both threading and grooving insert geometries.

Key Features

• CoroThread 266 series, style 266.RL for internal right-hand threading
• Coolant-through design for improved chip evacuation and extended insert life
• Screw-clamp insert holding for secure, repeatable insert indexing
• 3/8-inch insert inscribed circle accepts a wide range of 266-series inserts
• Pitch range of 64 to 8 TPI covers a broad spectrum of thread forms
• Steel construction provides shank rigidity in small-bore threading applications

Compatibility

Compatible inserts include: 266RL-16AC01F080E, 266RL-16AC01F100E, 266RL-16AC01F120E, 266RL-16AC01F140E, 266RL-16AC01F160E, 266RL-16MM01A050M, 266RL-16MM01A075M, 266RL-16MM01A100M, 266RL-16MM01A125M, 266RL-16MM01A150M, 266RL-16MM01A175M, and the 266RL-16MM family as specified by SANDVIK COROMANT.

Installation Notes

Installation is performed by a qualified machinist or CNC setup technician. Power down the machine and confirm spindle lock before mounting or removing the toolholder. Use the correct torque driver for the insert clamping screw per the insert manufacturer's documentation; do not overtighten. Verify coolant-through port alignment with the machine turret supply before beginning cuts.