Hertel H59875807 Boring Insert TPGH321HM1 HT410B Carbide

Product Description

The HERTEL H59875807 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 (TPGH) geometry, it carries an inscribed circle of 3/8 inches (0.3750 inches decimal) and a thickness of 1/8 inches (0.1270 inches decimal). The 0.021-inch corner radius and 11-degree relief angle suit finishing and semi-finishing passes in cast iron, non-ferrous metals, and general-purpose materials at the C2 carbide material grade. The uncoated surface finish makes it well suited for applications where coating adhesion or heat buildup is a concern. Chipbreaker geometry HM1 helps control chip flow in tight boring bar setups. Machinists and tool crib personnel handling precision turning work are the primary users of this insert.

This insert fits standard TPGH-style screw-on boring bar holders used in job shop, production machining, and maintenance turning applications. It is appropriate for light to medium-depth boring passes where a sharp, uncoated carbide edge is preferred over coated alternatives. The 60-degree included angle and screw-clamping holding method make it compatible with common indexable boring bar systems that accept triangular TPGH-pocket geometry. Applications range from small-diameter bore finishing on ferrous and non-ferrous workpieces to general internal turning in close-tolerance work.

Key Features

• Solid carbide construction at material grade C2 for rigidity and edge retention
• Uncoated finish suited for non-ferrous and cast iron machining where sharp edge is critical
• 60-degree triangle shape (TPGH) with screw-on insert holding method for secure clamping
• 0.021-inch corner radius for controlled surface finish on finishing and semi-finishing passes
• 11-degree relief angle reduces rubbing and supports free-cutting action in boring applications
• HM1 chipbreaker geometry assists chip control in confined internal turning setups

Compatibility

Designed as an OEM-style replacement insert for indexable boring bars and holders that accept TPGH-pocket triangular inserts with a 3/8-inch inscribed circle and screw-on clamping.

Installation Notes

Installation is performed by qualified machinists or toolroom technicians. Always index or replace inserts with the machine fully stopped and the spindle locked before handling cutting edges. Use the correct torque driver or insert screw tool specified by the boring bar manufacturer to seat the clamping screw — overtightening can crack the carbide. Inspect the insert pocket and clamping screw for wear or debris before seating a new insert to ensure proper edge positioning and runout.