Sumitomo 191R712 TPMN322 AC420K Carbide Turning Insert

Product Description

The SUMITOMO 191R712 is a solid carbide coated turning insert designed for precision metal cutting on CNC lathes and turning centers. It carries the TPMN322 designation with manufacturer grade AC420K and is produced using a CVD coating process. The insert features a 60-degree triangular shape with a positive rake geometry and an 11-degree relief angle, giving it a clean cutting action suited for finishing and semi-finishing operations. At 0.6496 inches in length with a 3/8-inch inscribed circle and a 1/32-inch corner radius, this insert fits standard TPMN-style toolholders and is installed by machinists and toolroom technicians working on production turning applications.

This insert is engineered primarily for cutting cast iron workpieces, which aligns with the AC420K grade designation and its CVD coating. It suits both light and moderate stock removal in turning operations where consistent tool life and dimensional accuracy are priorities. The TPMN-style geometry with a chip breaker code of N indicates a flat-top configuration suited to controlled chip flow in ferrous materials. It is sold individually and is appropriate for shops running dedicated insert programs on cast iron components such as housings, brackets, and manifolds.

Key Features

• CVD-coated carbide construction for extended tool life in cast iron cutting
• TPMN322 insert style with 60-degree triangular shape and positive rake geometry
• 11-degree relief angle for reduced cutting forces and clean edge engagement
• 1/32-inch corner radius for controlled surface finish in finishing passes
• Clamp-style insert holding method compatible with standard TPMN toolholders
• Meets ANSI and ISO 13399 standards; ISO code TPMN160308

Compatibility

Designed as an OEM-style replacement or direct-fit insert for TPMN-style toolholders accepting a 322 size code insert with a 3/8-inch inscribed circle and clamp-style holding method.

Installation Notes

This insert is seated and clamped by a machinist or toolroom technician using the appropriate TPMN-style toolholder and clamping hardware. Power down and lock out the machine spindle before changing inserts. Use the correct torx or hex key to torque the clamp screw to the toolholder specification without over-tightening, which can crack the carbide. Inspect the insert seat for chips or debris before installation to ensure proper seating and accurate tool nose position.