Kennametal 5591154 VBMT221LF Carbide Turning Insert

Product Description

The KENNAMETAL 5591154 is a solid carbide turning insert with ANSI insert code VBMT221 and ISO code VBMT110304LF, designed for precision finishing and light machining operations. It carries the KCM25B grade designation and features a multilayer CVD coating consisting of TiCN, Al2O3, and TiOCN applied via MTCVD process. The 35-degree diamond (rhombic) shape provides a sharp, positive rake angle of 5 degrees with a 5-degree relief angle and a honed cutting edge style. With a 0.0156-inch corner radius and a 0.25-inch inscribed circle, this insert suits applications where tight tolerances and fine surface finishes are required. Licensed HVAC, machining, and metalworking professionals specify this insert for ferrous and exotic-alloy turning work.

This insert is rated for use on steel, stainless steel, superalloys, and titanium workpiece materials, corresponding to ISO material codes P and M. The LF chip breaker geometry is optimized for finishing and light machining passes, keeping chip control predictable at lower depths of cut. It supports multiple operations including turning, facing, boring, back turning, and back boring, making it a versatile option for CNC lathe setups where a single insert geometry needs to handle varied tool paths. The screw-on holding method provides secure clamping and repeatable indexing during high-precision runs.

Key Features

• KCM25B grade with multilayer CVD coating: TiCN, Al2O3, and TiOCN for high toughness on steel and moderate wear resistance on stainless steel
• 35-degree diamond (V) insert shape with positive rake and positive side clearance for reduced cutting forces
• LF chip breaker geometry suited for finishing and light machining operations
• 2 cutting edges per insert; screw-on holding method for secure, repeatable indexing
• Honed cutting edge style minimizes micro-chipping on difficult-to-machine alloys including superalloys and titanium
• Meets ANSI and ISO standards; multi-use application across turning, facing, boring, back turning, and back boring

Compatibility

Designed for use in screw-on style VBMT toolholders conforming to ANSI and ISO insert seating standards. Compatible with toolholders accepting a VBMT 221 or VBMT 110304 insert seat geometry. Verify holder pocket clearance angle (B clearance, M tolerance) before installation.

Installation Notes

Installation should be performed by a qualified machinist or CNC setup technician with the machine fully stopped, spindle locked, and all energy sources isolated before indexing or replacing inserts. Use the appropriate torx or hex key to torque the screw-on clamp fastener to the toolholder manufacturer's specified value. Inspect the insert pocket and seating surface for chips or debris before seating the insert, as contamination in the pocket can cause insert rocking and premature edge failure. Do not exceed the maximum depth of cut of 0.2903 inches stated for this insert geometry.