Kennametal 4040139 Indexable Drill Insert Sppxmd KCU25

Product Description

The KENNAMETAL 4040139 is a solid carbide indexable drill insert in the SPPX style with an MD chipbreaker geometry, designed for use in indexable drill bodies on CNC machining centers and manual lathes. It carries a KCU25 manufacturer grade and features a CVD-applied multilayer coating of TiCN and Al2O3 for wear resistance and thermal stability during cutting operations. The insert has a 0.494-inch inscribed circle, a thickness of 0.1875 inches, and a corner radius of 0.0469 inches. This insert is installed and replaced by machinists and tooling technicians in production and job-shop environments where controlled hole-making and drilling cycle reliability are critical.

This insert suits applications in general-purpose drilling of ferrous and non-ferrous materials where C2 and C6 material grade classifications apply. The MD chipbreaker promotes chip control in through-hole and blind-hole drilling operations at moderate to high cutting speeds. It is appropriate for use in production environments where insert indexing time and consistent tool life are key operational factors. The CVD coating provides a hard outer layer that resists crater wear and flank wear across a broad range of workpiece materials.

Key Features

• SPPX insert style with MD chipbreaker geometry for controlled chip evacuation
• KCU25 grade solid carbide substrate for toughness in interrupted and continuous cuts
• CVD-applied TiCN and Al2O3 multilayer coating for wear and thermal resistance
• 0.494-inch inscribed circle and 0.0469-inch corner radius for precise dimensional fitment
• Insert size designation 120412 for direct cross-reference in tooling catalogs
• Sold individually with a minimum order quantity of 5 units

Compatibility

Designed for indexable drill bodies that accept SPPX-style inserts with a 0.494-inch inscribed circle. Verify seat geometry, clamping screw size, and insert pocket dimensions against the drill body specification before installation.

Installation Notes

Insert replacement should be performed by a qualified machinist or tooling technician with the machine powered down and the spindle locked. Use the correct torque wrench and insert screw specified by the drill body manufacturer when seating the insert — overtightening the clamping screw can fracture the carbide substrate. Inspect the insert pocket and seating surfaces for chips or debris before installing a fresh insert. Index or replace the insert at the first sign of chipping, excessive flank wear, or surface finish degradation on the workpiece.