Hertel H59874511 Boring Insert TPCG221 HT630B Cermet

Product Description

The HERTEL H59874511 is a cermet uncoated boring insert designed for precision material removal in turning and boring operations. Manufactured to TPCG221 insert geometry, it features a 60-degree triangular shape with an 11-degree relief angle and a 1/64-inch (0.0150-inch) corner radius. The insert measures 1/4-inch inscribed circle and 3/32-inch thickness. Classified under material grade C8 and manufacturer grade HT630B, this insert is intended for use in screw-holding toolholders and is suited for left-hand cutting applications. Cermet construction provides hardness and wear resistance appropriate for finishing and semi-finishing cuts in steel and cast iron.

This insert is applied in CNC turning centers, boring bars, and manual lathes where precise dimensional control is required. The TPCG style with left-hand orientation suits specific toolholder configurations used in internal boring and turning operations. The uncoated cermet substrate performs well in dry or lightly lubricated finish-cut conditions on ferrous workpieces. Machinists and toolroom professionals working with tight tolerances on steel and similar materials will find the geometry and grade appropriate for controlled-depth passes.

Key Features

• TPCG221 insert geometry with 60-degree triangular shape and 11-degree relief angle
• Cermet uncoated substrate rated at material grade C8 for wear resistance in finishing applications
• 1/64-inch corner radius (0.0150 inch) for controlled surface finish and edge strength
• 1/4-inch inscribed circle diameter for compatibility with standard TPCG-style toolholders
• Left-hand cutting orientation with screw-holding insert retention method
• Bright/uncoated finish suitable for dry and semi-dry cutting conditions

Compatibility

Designed for use in TPCG-style screw-clamp toolholders accepting a 221 insert size with a 1/4-inch inscribed circle. Left-hand holder configurations are required. Verify toolholder pocket geometry and seating before installation.

Installation Notes

Insert installation should be performed by a qualified machinist or toolroom professional with the machine fully powered down and locked out before changing inserts. Use the appropriate torx or hex key to seat the clamping screw to the toolholder manufacturer's specified method — do not overtighten, as cermet inserts are brittle and susceptible to fracture under excessive clamping force. Inspect the insert pocket and seating surface for chips or debris before seating the insert. Confirm insert orientation matches the left-hand designation of the toolholder before resuming operation.