Tungaloy 6856770 Turning Insert CPMT21.51PS AH725

Product Description

The TUNGALOY 6856770 is a solid carbide turning insert designated by ISO code CPMT21.51PS in manufacturer grade AH725. This insert features a TiAlN coating applied via PVD process, an 80-degree diamond shape, and a positive rake geometry with a honed cutting edge. The inscribed circle measures 0.25 inches, the insert length is 0.256 inches, and the corner radius is 0.0157 inches. With 2 cutting edges and a screw-type holding method, it is suited for precision turning, facing, and boring operations on CNC lathes and turning centers. Licensed machinists and toolroom technicians are the primary installers and operators.

This insert is designed for use across a broad range of workpiece materials including steel, stainless steel, cast iron, non-ferrous metals, superalloys, titanium, and hard materials. It is well suited for medium finishing to semi-roughing applications in production turning environments. The PS chip breaker geometry supports stable chip control across these material groups. The maximum depth of cut is 0.0984 inches, making it appropriate for light to moderate material removal passes in both conventional and high-speed turning setups.

Key Features

• TiAlN coating via PVD process for wear resistance across diverse workpiece materials
• 80-degree diamond insert shape with positive rake for reduced cutting forces
• PS chip breaker for effective chip control in turning, facing, and boring
• Honed cutting edge for edge stability and consistent surface finish
• 2 usable cutting edges per insert for extended tool economy
• Screw-type insert holding compatible with standard CPMT toolholders

Compatibility

Designed as an OEM-style replacement and standard production insert for CPMT-style toolholders conforming to ANSI and ISO mounting standards. Compatible material grades include P15, P30, M15, M30, K25, K30, S15, and S25 per ISO classification.

Installation Notes

Installation is performed by machinists or toolroom technicians using the appropriate torque wrench for the insert screw specified by the toolholder manufacturer. Power down and lock out the machine spindle before seating or indexing the insert. Inspect the insert pocket and seating surface for chips or debris before installation to ensure proper insert contact and prevent premature edge failure. Follow the toolholder manufacturer's clamping torque specification for the screw size used.