Hertel H00208207 TPMT321GP Boring Insert Solid Carbide

Product Description

The HERTEL H00208207 is a solid carbide boring insert designed for precision internal turning and boring operations on CNC and manual lathes. Formed in a 60-degree triangle (TPMT) geometry with a GP chipbreaker, this insert carries a Titanium Nitride (TiN) coating applied via PVD process, which increases surface hardness and extends tool life in steel and cast iron applications. The 11-degree relief angle reduces cutting edge friction and helps maintain dimensional accuracy in tight-tolerance bores. At 0.125 inches thick with a 0.375-inch inscribed circle, this insert seats securely via screw-hold clamping. Material grade C5 makes it suitable for general-purpose machining of ferrous materials at moderate cutting speeds.

This insert is intended for boring bars and indexable toolholders accepting TPMT321 geometry inserts. It is used in production and maintenance machining environments including job shops, aerospace component work, and general metalworking. The screw-in holding method suits standard TPMT-compatible boring bar bodies. Machinists working in steel, cast iron, and similar ferrous materials will find the HP520B grade and GP chipbreaker geometry appropriate for roughing to semi-finishing passes in internal diameter operations.

Key Features

• Solid carbide construction, material grade C5, for rigidity and wear resistance in ferrous machining
• TiN coating via PVD process increases surface hardness and reduces built-up edge
• 60-degree triangle TPMT geometry with GP chipbreaker for controlled chip evacuation
• 11-degree relief angle reduces rubbing and supports accurate bore sizing
• 1/64-inch (0.015-inch) corner radius balances edge strength and surface finish quality
• Screw-hold clamping method for positive insert retention during boring passes

Compatibility

Designed as an OEM-style replacement or standard-fit insert for boring bars and indexable toolholders accepting TPMT321 insert geometry with screw-in clamping.

Installation Notes

Installation is performed by qualified machinists or toolroom personnel. Power down and lock out the machine spindle before indexing or replacing inserts. Use the correct torque driver for the clamping screw to avoid cracking the carbide body or stripping the seat. Inspect the insert pocket and seat face for chips or debris before seating the new insert.