Hertel 8851965 CPGT21.51 Cermet Turning Insert

Product Description

The HERTEL 8851965 is a cermet uncoated turning insert designed for precision metal cutting operations on CNC and manual lathes. Manufactured to CPGT21.51 style with an 80-degree diamond insert shape, it delivers clean, accurate cuts in finishing and light roughing applications. The insert features a positive rake geometry with an 11-degree relief angle and a T-style chip breaker, promoting efficient chip evacuation and reduced cutting forces. With a 0.25-inch inscribed circle and a 0.0156-inch (1/64 inch) corner radius, this insert suits tight-tolerance turning work. It is held in place via screw clamping and is classified with a G tolerance and P clearance code.

This insert is suited for turning operations on ferrous and non-ferrous workpiece materials where cermet grade HT115CR provides a balance of wear resistance and edge sharpness. Typical applications include finish turning of steel and cast iron components in production shops, tool-and-die environments, and general machining facilities. The neutral hand orientation makes it compatible with standard right-hand turning toolholders. Machinists and CNC operators working in high-precision, low-feed finishing passes will find this insert well-suited to their requirements.

Key Features

• CPGT21.51 insert style with 80-degree diamond shape for precise turning geometry
• Cermet uncoated construction in grade HT115CR for wear resistance in finishing cuts
• Positive rake angle reduces cutting forces and heat generation at the edge
• T-style chip breaker promotes controlled chip flow during continuous turning
• Screw-clamping insert holding method for secure, repeatable seating in the toolholder
• Neutral hand orientation compatible with standard right-hand turning setups

Compatibility

Designed as a direct-fit replacement for CPGT21.51-style screw-on turning toolholders accepting an 80-degree diamond insert with a 0.25-inch inscribed circle and screw-clamping retention.

Installation Notes

Installation is performed by qualified machinists or CNC tool-setup personnel. Power down and lock out the machine spindle before indexing or replacing inserts. Use the appropriate torx or hex key as specified by the toolholder manufacturer to seat the clamping screw to the toolholder's recommended torque. Inspect the insert pocket and clamping screw for wear or debris before seating the new insert to ensure proper edge height and runout.