Allied 4C21P-20.5 Spade Drill Insert 20.50mm Carbide

Product Description

The ALLIED MACHINE AND ENGINEERING 4C21P-20.5 is a solid carbide spade drill insert designed for high-performance hole-making operations in demanding metalworking applications. With a 20.50 mm cutting diameter, a 132-degree point angle, and a GEN2 T-A series seat size 1 configuration, this insert is engineered for precision drilling in difficult-to-machine materials. The AM300 PVD coating provides a hard, wear-resistant surface layer that extends tool life across aggressive cutting cycles. Licensed machinists and tooling technicians working on CNC machining centers and drill press setups are the typical end users for this insert type.

This insert is suited for machining stainless steel, cast iron, non-ferrous metals, super-alloys, and titanium — workpiece material codes M, K, N, and S. It fits into GEN2 T-A series spade drill holders at seat size 1, making it a direct drop-in replacement for worn inserts in that holder family. Both production shops running high-volume parts and job shops handling specialty alloy work will find this insert appropriate for their requirements. The minimum order quantity is 2 units; each package contains 1 insert.

Key Features

• Solid carbide construction at manufacturer grade C2 (K20) for rigidity and heat resistance
• AM300 PVD coating classification for extended wear life in high-temperature cutting
• 132-degree point angle optimized for controlled entry and reduced thrust force
• GEN2 T-A series, seat size 1 — direct replacement fit for compatible holders
• Rated for stainless steel, cast iron, non-ferrous metals, super-alloys, and titanium
• Compact insert profile: 1.5 inches wide, 1.5 inches long, 0.38 inches in height, 0.1563 inches thick

Compatibility

Designed for use with GEN2 T-A series spade drill holders at seat size 1. Compatible workpiece materials include stainless steel, cast iron, non-ferrous metals, super-alloys, and titanium (material codes M, K, N, and S).

Installation Notes

Installation is performed by a qualified machinist or tooling technician. Before swapping inserts, ensure the spindle is fully stopped, locked out, and the holder is secured in a bench vise or tool block. Seat the insert fully into the holder pocket and verify it is flush and properly torqued per the holder manufacturer specification before returning the tool to service. Inspect the seat for chips or debris that could affect insert seating and dimensional accuracy.