Hertel H59874131 Boring Insert TPCB221 Solid Carbide

Product Description

The HERTEL H59874131 is a solid carbide boring insert designed for precision internal turning and boring operations on CNC and manual lathes. Manufactured to TPCB221 insert geometry, it features a 60-degree triangular shape with an 11-degree relief angle and an uncoated finish suited for general-purpose machining in C1 grade carbide. The inscribed circle measures 0.25 inches, thickness is 0.096 inches, and the corner radius is 0.015 inches (1/64 inch). Grade HT540B identifies the specific carbide formulation and geometry class. The insert is held in place by a screw-type clamping system, making it compatible with standard TPCB-style boring bars and toolholders.

This insert is used in boring and internal turning applications across metalworking, machining, and tool-and-die trades. It is appropriate for residential shop, job shop, and production floor environments where close-tolerance internal diameters are required. The uncoated solid carbide construction makes it a practical choice for cast iron, non-ferrous metals, and similar materials where coating adhesion or heat buildup is a concern. Machinists and tool technicians select this insert when tight corner radius control and consistent edge geometry are priorities.

Key Features

• TPCB221 insert style with 60-degree triangular geometry and 11-degree relief angle
• Solid carbide construction, grade C1, manufacturer grade HT540B
• Uncoated finish for general-purpose boring and internal turning
• Corner radius of 0.015 inches for controlled surface finish
• Screw-type insert holding method for secure, repeatable seating
• Inscribed circle of 0.25 inches and thickness of 0.096 inches

Compatibility

Designed as a direct-fit replacement insert for TPCB-style boring bars and toolholders accepting 221 size code inserts with screw-type clamping.

Installation Notes

This insert is installed and replaced by machinists or tool technicians using appropriate insert clamping screws and a torx or hex key as specified by the toolholder manufacturer. Power down and lock out the machine spindle before changing inserts. Inspect the insert pocket and clamping screw for wear or damage before seating a new insert. Do not overtighten the clamping screw beyond the toolholder manufacturer specification.