Sandvik Coromant 5908991 Turning Insert CNMG644-SMR

Product Description

The SANDVIK COROMANT 5908991 is a CNMG-style indexable turning insert in the T-Max P series, designed for external turning operations on CNC lathes and turning centers. Manufactured from solid carbide with a PVD-applied TiAlN coating, this insert is engineered for cutting stainless steel and superalloy or titanium workpieces where heat resistance and edge integrity are critical. The 80-degree diamond shape provides a strong cutting edge geometry, while the SMR chip breaker promotes controlled chip formation at moderate to high cutting depths. With a 3/4 inch inscribed circle and a 1/16 inch corner radius, this insert suits medium-duty turning applications requiring consistent surface finish and extended tool life.

This insert is suited for shop-floor and production environments running stainless steel, superalloys, and titanium components. The neutral hand orientation makes it compatible with standard CNMG toolholders used in both turning centers and manual lathes. Four available cutting edges per insert help reduce tooling cost per part in high-cycle production runs. The T-Max P series is a common platform in aerospace, medical, and general precision machining environments where difficult-to-machine materials are routinely processed.

Key Features

• PVD TiAlN coating provides thermal stability and oxidation resistance when cutting stainless steel and superalloys
• SMR chip breaker geometry controls chip formation across a range of feed rates and depths of cut
• 80-degree diamond insert shape (CNMG) delivers strong cutting edge with versatile approach angle options
• Four cutting edges per insert maximize tooling economy in production turning
• Neutral hand designation fits standard CNMG-compatible toolholders without special orientation requirements
• Clamp and pin holding method ensures secure seating and repeatable edge positioning

Compatibility

Designed for use in CNMG-style toolholders that accept inserts with a 3/4 inch inscribed circle and clamp-and-pin holding. ISO equivalent designation is CNMG190616-SMR 1105. Primary workpiece material is stainless steel (ISO material code M); secondary workpiece materials are superalloys and titanium (ISO material code S).

Installation Notes

Installation is performed by qualified machinists or tooling technicians. Ensure the machine spindle is fully stopped and the turret is indexed to a safe position before seating or indexing the insert. Use the manufacturer-specified torque driver for the clamping screw to avoid insert cracking or improper seating. Inspect the toolholder pocket and locating pin for wear or debris before installing a new cutting edge.