Sandvik Coromant 5721756 Indexable Boring Bar Steel

Product Description

The SANDVIK COROMANT 5721756 is a steel indexable boring bar from the CoroTurn 111 series, designed for precision internal boring and turning operations on CNC lathes and machining centers. It features a 3/8 inch shank diameter and a minimum bore diameter of 0.4803 inches (12.20 mm), making it suited for small-bore internal machining work. The toolholder uses screw clamping to secure a single CPMT 21.51 insert, delivering a positive rake angle of 4 degrees and a 4-degree lead angle. Coolant-through capability is supported, helping to manage chip evacuation and heat in demanding cutting conditions. Machinists and CNC operators in production shops and job shops are the typical end users.

This boring bar is used in both boring and turning applications, functioning as a multi-use toolholder in those operations. The A-SCLP toolholder style and right-hand cut orientation suit standard lathe setups where internal diameter finishing or roughing is required. The 6-inch overall length provides adequate reach for many common bore depths while maintaining rigidity at the 3/8 inch shank size. The center-to-cutting-edge distance is 0.25 inches (6.35 mm), and the back-of-bar-to-cutting-edge measurement matches the 6-inch overall length at 152.40 mm.

Key Features

• CoroTurn 111 series toolholder with A-SCLP style designation
• Minimum bore diameter of 0.4803 inches (12.20 mm) for small-bore internal work
• Screw clamping insert retention with positive rake geometry at 4-degree rake angle
• Coolant-through design for improved chip control and thermal management
• Multi-use capability supporting both boring and turning operations
• Steel construction with 6-inch overall length and 3/8 inch shank diameter

Compatibility

Designed to accept CPMT 21.51 inserts with a 1/4 inch inscribed circle. Uses one insert per toolholder. Compatible with standard 3/8 inch shank tooling setups on CNC lathes and boring machines configured for right-hand cutting.

Installation Notes

Installation should be performed by a qualified machinist or CNC setup technician with the machine powered down and in a safe lockout-tagout state before toolholder changes. Verify shank bore and clamping mechanism compatibility with the turret or toolpost before mounting. Use the correct torque driver for the screw clamp to avoid insert seat damage. Inspect insert seating and cutting edge condition before resuming operation.