Allied Machine 451H-21 Spade Drill Insert 21mm Cobalt

Product Description

The ALLIED MACHINE AND ENGINEERING 451H-21 is a cobalt spade drill insert designed for high-performance drilling in demanding metalworking applications. Part of the GEN2 T-A series, this insert features a 132-degree point angle and a Super Cobalt substrate with an AM200 PVD coating. The combination of cobalt toughness and PVD surface treatment extends tool life and supports higher cutting speeds compared to standard HSS inserts. It measures 21.00 mm in diameter with a Seat Size 1 designation and a thickness of 0.1563 inches. Machinists and tool-and-die professionals rely on this insert for consistent hole quality in production environments.

This insert is engineered for use in steel, stainless steel, cast iron, superalloys, titanium, and hard materials, covering ISO material codes P, M, K, S, and H. The GEN2 T-A spade drill system is suited for CNC machining centers and manual drill presses where interchangeable insert tooling is used to reduce tooling cost and setup time. It is a direct drop-in replacement for compatible T-A series holders of the appropriate seat size.

Key Features

• 21.00 mm cutting diameter with Seat Size 1 for precise holder fit
• 132-degree point angle reduces thrust and improves centering on entry
• Super Cobalt substrate provides increased hardness and heat resistance over standard cobalt grades
• AM200 PVD coating enhances wear resistance and surface finish in ferrous and hard materials
• Compatible with multiple ISO workpiece material categories: P, M, K, S, and H
• GEN2 T-A series design supports quick insert changes without removing the holder from the spindle

Compatibility

Designed for use with GEN2 T-A series spade drill holders accepting a Seat Size 1 insert. Specific holder compatibility should be verified against the Allied Machine and Engineering GEN2 T-A holder selection guide using the 21.00 mm diameter and seat size designations.

Installation Notes

Insert installation and replacement should be performed by a qualified machinist with the machine powered off and the spindle fully stopped. Use the appropriate torque wrench and insert screws specified for the T-A holder to secure the insert without over-tightening, which can damage the seating surface. Inspect the holder pocket and seating surfaces for chips or wear before installing a new insert. Follow your facility safety procedures and machine tool manufacturer guidelines when changing cutting tool inserts.