Kennametal 1557820 Ceramic Turning Insert VNGA331T0420

Product Description

The KENNAMETAL 1557820 is a ceramic turning insert with ANSI designation VNGA331T0420 and manufacturer grade KY4400. Constructed from an alumina TiCN base material with a PVD-applied TiN coating, this insert is engineered for cutting hard materials where thermal resistance and edge integrity are critical. The V-shape 35-degree diamond geometry with a T-land cutting edge style and flat-top chip breaker delivers controlled chip flow during interrupted and continuous hard-turning operations. With four available cutting edges and negative rake geometry, the insert maximizes tool life and cost efficiency per edge. It is installed by machinists and CNC tooling technicians running precision turning, facing, boring, back turning, and back boring operations.

This insert is suited for hard-turning applications in both production and job-shop environments. The KENLOC series designation indicates compatibility with KENNAMETAL KENLOC-style toolholders that accept VNGA-geometry inserts with clamp and pin holding. Typical workpiece materials include hardened steels and other hard-to-machine alloys classified under primary workpiece material code H. Maximum depth of cut is 0.0492 inches (1.25 mm), making this insert appropriate for finishing and light roughing passes on hardened components where dimensional accuracy is required.

Key Features

• Alumina TiCN ceramic substrate with PVD TiN coating for thermal and wear resistance in hard-material turning
• 35-degree diamond (rhombic) V-shape with T-land cutting edge for improved edge strength on hard workpieces
• Four cutting edges per insert for extended tool life and reduced cost per edge
• Flat-top chip breaker geometry for consistent chip control during facing, boring, and back-turning operations
• Neutral hand orientation compatible with both left- and right-hand toolholder setups
• Clamp and pin holding method for secure insert retention under high cutting forces

Compatibility

Designed for use in KENNAMETAL KENLOC-series toolholders accepting VNGA-style inserts with ANSI size code 331 and ISO size code 160404. Holding method requires a toolholder with clamp and pin retention.

Installation Notes

Insert installation and indexing should be performed by a qualified machinist or CNC tooling technician with the machine fully powered down and the spindle locked. Use the appropriate torx or hex key to seat the clamping screw to the toolholder manufacturer's specified torque without applying excessive force that could chip the ceramic edge. Ceramic inserts are brittle compared to carbide; avoid lateral impact during handling and storage. Inspect the seating pocket and pin bore for chips or debris before each insert index to ensure full and accurate seating.