Sumitomo 166QEHH Turning Insert Pcbn Ticn 3/8 Ic Diamond

Product Description

The SUMITOMO 166QEHH is a polycrystalline cubic boron nitride (PCBN) turning insert engineered for hard-turning applications on steel workpieces. Coated with TiCN via a PVD process, this insert delivers high wear resistance and thermal stability at the cutting edge. It features an 80-degree diamond insert shape, a 3/8-inch inscribed circle, and a 1/64-inch corner radius. The screw-holding method provides secure clamping in compatible toolholders. This insert is specified by machinists and CNC operators working in production turning environments where close tolerances and surface finish on hardened steel are required.

The 166QEHH is designed for turning operations where the primary workpiece material is steel, including hardened and hard-to-machine grades. The positive rake geometry and chip breaker designation A support controlled chip flow and reduced cutting forces. It is suited for finishing and semi-finishing passes in CNC turning centers and manual lathes equipped with appropriate CCGA-style toolholders. Package quantity is 1 insert per unit.

Key Features

• PCBN insert material provides superior hardness and edge retention for steel turning
• TiCN PVD coating enhances wear resistance and surface finish quality
• 80-degree diamond insert shape (Shape Code C) with 2 cutting edges
• Positive rake geometry reduces cutting forces on hardened workpieces
• Screw-held insert style (2NC-CCGA) for repeatable, rigid toolholder engagement
• Chip breaker designation A supports controlled chip evacuation in finish turning

Compatibility

Designed for use in CCGA-style screw-held toolholders conforming to ANSI and ISO 13399 standards. ISO code reference is 2NC-CCGW09T304. Verify toolholder bore and pocket geometry match the 0.1732-inch hole diameter and CCGA insert seat before installation.

Installation Notes

Installation should be performed by a qualified machinist or toolroom technician. Power down and lock out the machine spindle before seating or removing the insert. Use the appropriate torx or hex key to torque the clamping screw into the toolholder pocket; do not overtighten, as PCBN inserts are brittle and susceptible to edge chipping from improper seating. Inspect the insert pocket for chips or debris before installing a new insert.