Sumitomo 16GC276 Pcbn Turning Insert BN350 Triangle

Product Description

The SUMITOMO 16GC276 is a NUTPGA221 polycrystalline cubic boron nitride (PCBN) turning insert designed for precision machining of hard materials. It features a triangular insert shape with a 60-degree included angle, a 1/4-inch inscribed circle (0.2500 inches), and a 1/64-inch corner radius (0.0156 inches). The insert thickness is 1/8 inch (0.1250 inches) and the part carries the BN350 manufacturer grade. The uncoated PCBN substrate is engineered for high-hardness workpiece materials where conventional carbide inserts lose performance. This insert is installed by CNC machinists and toolroom technicians working on turning centers and CNC lathes.

This insert is suited for single-point turning operations on hard materials, including hardened steels and wear-resistant alloys, in both light and medium finishing applications. The positive rake geometry and P clearance code support clean chip evacuation and reduced cutting forces. The screw-held mounting method (insert holding method: screw) keeps setup repeatable on standard toolholders conforming to ANSI and ISO 13399 standards. It is appropriate for high-precision production turning in industrial and toolroom environments where surface finish and dimensional control on hard workpieces are priorities.

Key Features

• PCBN insert material for hard-material turning where carbide is unsuitable
• BN350 grade, uncoated, positive rake geometry (clearance code P)
• 1/4-inch inscribed circle, 1/8-inch insert thickness, 1/64-inch corner radius
• Triangular insert shape (60-degree included angle) with 1 cutting edge
• Screw-held mounting for secure, repeatable toolholder positioning
• Conforms to ANSI NUTPGA221 and ISO NU-TPGW110304 designations

Compatibility

Designed as an OEM-style replacement or standard-fit insert for ANSI NUTPGA221 and ISO NU-TPGW110304 toolholder pockets on turning centers and CNC lathes configured for triangular screw-held inserts in hard-material (H-grade workpiece) applications.

Installation Notes

Installation is performed by a qualified machinist or toolroom technician following standard insert-change procedures on a powered-down or E-stopped CNC turning center. Secure the insert using the manufacturer-specified screw torque listed in the toolholder documentation. Inspect the insert pocket and seating surface for debris or damage before seating the new insert. Follow shop safety protocols and applicable machine-tool standards when handling PCBN inserts, as edges are extremely sharp.