Sumitomo 166QEJK Pcbn Turning Insert 80 Degree Diamond

Product Description

The SUMITOMO 166QEJK is a polycrystalline cubic boron nitride (PCBN) turning insert designed for high-speed machining of hard and abrasive workpiece materials. It carries the ANSI designation 2NCCNGA432 and ISO code 2NC-CNGA120408, placing it in the CNG series with a diamond (C) insert shape. The insert features a TiCN coating applied via PVD process, a negative rake geometry, and a neutral hand orientation. With a 0.5 inch inscribed circle and a 0.03125 inch corner radius, it is suited for precision turning operations where tight tolerances and tool life are critical. Two cutting edges are available per insert.

This insert is intended for turning applications on cast iron, steel, and superalloy workpieces. It is commonly used in production turning on CNC lathes and turning centers where PCBN tooling is specified for extended tool life, high surface finish requirements, or hard-turning operations that would rapidly wear carbide. The CNGA-style insert seats into standard clamp-and-pin toolholders. It is appropriate for both roughing and finishing passes depending on depth of cut and feed rate selection.

Key Features

• PCBN insert material for hard and abrasive workpiece capability in cast iron, steel, and superalloy
• TiCN coating via PVD process for improved wear resistance and surface integrity
• 80 degree diamond insert shape provides a strong cutting edge with good approach angle flexibility
• Negative rake geometry supports interrupted cuts and robust edge strength
• 0 degree relief angle (clearance code N) with tolerance code G for consistent seating accuracy
• Two cutting edges per insert for cost-effective tooling usage
• Compatible with standard clamp and pin insert holding systems

Compatibility

Designed for use in standard CNGA-style clamp-and-pin toolholders accepting a 432 insert size with a 0.2031 inch hole diameter. Conforms to ANSI and ISO 13399 standards. Verify toolholder specifications before installation.

Installation Notes

PCBN turning inserts should be installed by a qualified machinist or tooling technician familiar with indexable insert tooling. Ensure the machine spindle is fully stopped and the toolholder is secured before seating or indexing the insert. Use the appropriate torque wrench per toolholder manufacturer specifications when tightening the clamp screw. Inspect the insert pocket and locating pin for wear or debris before each insert change to maintain accurate seating and prevent premature edge failure.