Hertel H00208215 Boring Insert TPMT321GP HC620B Carbide

Product Description

The HERTEL H00208215 is a solid carbide boring insert designed for precision internal turning and boring operations on CNC and manual lathes. Configured in the TPMT style with a 60-degree triangular shape, this insert carries the HC620B manufacturer grade and features a multilayer CVD coating stack of TiN, TiC, TiCN, and TiN. That coating sequence improves wear resistance and thermal stability during continuous and interrupted cuts. The screw-clamping hold method keeps the insert securely indexed under load. With a 1/64-inch corner radius, the edge geometry targets finishing and semi-finishing passes where surface finish and dimensional accuracy matter most.

This insert is suited for boring applications in ferrous materials, consistent with C7 carbide material grade, which covers cast iron and hardened steels. It fits standard TPMT-style boring bars with a 3/8-inch inscribed circle seating. Machinists and toolroom technicians working in job shops, production facilities, or maintenance environments will find the GP chipbreaker geometry effective for controlling chip flow in through-bore and blind-bore configurations. The 11-degree relief angle provides clearance to minimize rubbing on the bore wall during operation.

Key Features

• TPMT321GP insert style with 60-degree triangular shape for three usable cutting edges
• Solid carbide construction with CVD-applied multilayer TiN, TiC, TiCN, TiN coating for extended tool life
• HC620B grade matched to C7 carbide classification, suited for cast iron and hardened ferrous materials
• 1/64-inch (0.0150-inch) corner radius for finishing and semi-finishing surface quality
• 11-degree relief angle reduces bore wall contact and minimizes flank wear
• Screw-clamping insert holding method ensures positive, repeatable indexing

Compatibility

Designed as a direct-fit replacement for TPMT321GP-style boring bars and toolholders accepting a 3/8-inch inscribed circle insert with screw-clamping retention.

Installation Notes

Insert installation should be performed by a qualified machinist or toolroom technician. Power down and lock out the machine spindle before indexing or replacing inserts. Use the correct torque screwdriver or wrench specified by the toolholder manufacturer when securing the clamp screw — do not overtighten. Inspect the toolholder pocket and seating surfaces for chips or debris before seating the insert to ensure accurate positioning and full edge engagement.