Hertel H00323089 Boring Insert TPGT21.51HF2 HP520B Carbide

Product Description

The HERTEL H00323089 is a solid carbide boring insert designed for precision internal turning and boring operations on CNC lathes and machining centers. Designated TPGT21.51HF2 in the HP520B grade, this insert features a 60-degree triangular shape with an 11-degree relief angle and a 1/64 inch (0.0150 inch) corner radius. The PVD-applied TiN coating enhances wear resistance and edge retention during finish boring passes. With a 1/4 inch inscribed circle and a thickness of 3/32 inch (0.0940 inch), this insert is sized for light-duty, high-precision boring applications. The HF2 chipbreaker geometry promotes reliable chip control at fine depths of cut.

This insert is suited for finish and semi-finish boring of ferrous and non-ferrous materials in both production and job-shop environments. The TPGT style and screw-clamping holding method make it compatible with standard TPGT-style boring bar pockets. The HP520B grade at the C5 material classification is appropriate for turning steel and cast iron at moderate to high cutting speeds. Machinists and CNC operators handling tight-tolerance bore work will find the geometry and coating well matched to finishing requirements.

Key Features

• Solid carbide construction in HP520B grade (C5 classification) for consistent tool life in steel and cast iron
• PVD TiN coating applied for improved wear resistance and reduced built-up edge
• HF2 chipbreaker geometry engineered for controlled chip formation during finish boring
• 60-degree triangular insert shape (TPGT style) with 11-degree relief angle for clearance in tight bores
• Screw-clamping holding method for secure, repeatable seating in compatible boring bars
• 1/64 inch corner radius for fine surface finishes on precision bore diameters

Compatibility

Designed as an OEM-style replacement insert for TPGT21.51-style boring bars and toolholders that accept screw-clamp TPGT inserts with a 1/4 inch inscribed circle.

Installation Notes

Installation of boring inserts should be performed by a qualified machinist or CNC operator with the machine in a powered-off and locked-out state. Use the appropriate torx or hex key to seat the clamping screw to the toolholder manufacturer's specification without overtightening, which can crack the carbide body. Inspect the insert pocket and screw threads for debris or damage before seating a new insert. Always verify insert orientation and overhang before resuming cutting operations.