Sumitomo 166REPQ Pcbn Turning Insert Diamond 55 Deg BNC2020

Product Description

The SUMITOMO 166REPQ is a Polycrystalline Cubic Boron Nitride (PCBN) turning insert designed for precision metal cutting in CNC and manual lathe applications. This insert carries the BNC2020 manufacturer grade with a PVD-applied coating for enhanced wear resistance and edge stability. It features a 55-degree diamond shape (Insert Shape Code D) with a positive rake geometry and a clearance code of C. The inscribed circle measures 3/8 inch (0.3750 inches), the insert thickness is 5/32 inch (0.1563 inches), and the corner radius is 0.0078 inches. With two cutting edges per insert, the 166REPQ delivers consistent performance in hard-turning operations on steel workpieces.

This insert is suited for hard turning of steel (Primary Workpiece Material Code H) in both production and job-shop environments. The 2NC-DCGA insert style and Series D designation place it in a standardized geometry family recognized under ANSI and ISO 13399 standards, making it a practical choice for machinists specifying indexed tooling on multi-pass finishing cuts. It is typically used in applications where conventional carbide inserts reach their limits, such as hardened steel turning at elevated surface speeds. Installation is screw-held, compatible with toolholders designed for the DCGA insert style.

Key Features

• PCBN insert material with PVD coating for extended tool life in hard steel turning
• 55-degree diamond insert shape with positive rake for reduced cutting forces
• BNC2020 grade with coated finish for thermal and abrasion resistance
• Two cutting edges per insert for cost-effective indexing
• Screw-held mounting method for secure, repeatable positioning
• Compliant with ANSI and ISO 13399 standards (ISO Code: 2NC-DCGW11T302)

Compatibility

Designed as an OEM-style replacement or direct-fit turning insert for toolholders accepting the 2NC-DCGA insert style in Series D geometry. Verify toolholder pocket specifications against the DCGA clearance and tolerance codes before installation.

Installation Notes

This insert is installed by a machinist or toolroom technician using the screw-held clamping method standard for indexed turning toolholders. Power down and lock out the machine before indexing or replacing inserts. Use the correct torque screwdriver for the insert screw to avoid seat damage — refer to the toolholder manufacturer's specification sheet for fastener torque values. Inspect the toolholder pocket for wear or debris before seating the insert.