Hertel H59874743 Boring Insert TPCH221 HC620B Carbide

Product Description

The HERTEL H59874743 is a solid carbide boring insert designed for precision internal boring operations on CNC lathes and machining centers. Manufactured to TPCH221 insert style standards, it features a triangular 60-degree included angle with an 11-degree relief angle and a 1/64-inch corner radius. The insert carries a multilayer CVD coating sequence of TiN, TiC, TiCN, and TiN, classified under manufacturer grade HC620B and material grade C7. This coating combination improves wear resistance and tool life in continuous and semi-continuous ferrous cutting applications. Machinists and CNC operators working in production turning environments will find this insert suited to finishing and light roughing passes on steel and cast iron.

This insert is intended for internal boring operations in precision machining environments, including job shops, production facilities, and toolroom settings. The TPCH221 geometry is a standard triangular screw-on insert held by a mechanical clamp or screw-in boring bar system. With a 1/4-inch inscribed circle and 3/32-inch thickness, it is sized for small-diameter boring bar bodies commonly used in tight-bore applications. Compatible toolholders must accept TPCH-style triangular inserts with the corresponding insert size code 221 and screw-on holding method.

Key Features

• Solid carbide substrate rated material grade C7 for steel and cast iron cutting
• Multilayer CVD coating: TiN, TiC, TiCN, TiN for extended wear resistance
• 60-degree triangular geometry with 11-degree relief angle for reduced cutting forces
• 1/64-inch corner radius suited to finishing and semi-finishing passes
• Screw-on holding method compatible with standard TPCH-style boring bar bodies
• Compact 1/4-inch inscribed circle for small-bore diameter applications

Compatibility

Designed as a replacement-style insert for boring bar toolholders that accept TPCH221 triangular screw-on inserts with a 1/4-inch inscribed circle and 3/32-inch thickness.

Installation Notes

Installation should be performed by a qualified machinist or CNC operator with the machine powered down and the spindle locked before changing inserts. Use the correct torque wrench and insert screw specified by the boring bar manufacturer to secure the insert without cracking the carbide substrate. Inspect the insert pocket seat for chips or debris before seating the insert, as contamination can cause insert rocking and premature edge failure. Verify tool offset and runout after installation before returning the machine to production cutting.