Allied Machine 138T-0404 is an Original T-A 4-1/8" spade drilling insert designed to be used with Allied’s T-A Replaceable Insert Drilling System. This 4-1/8" diameter insert provides a replaceable cutting edge for holemaking in metalworking, allowing quick edge changes without regrinding and preserving the established T-A geometry when used with a compatible drill body. The 138T-0404 designation identifies Allied’s spade drill insert in the 4-1/8" size class, commonly employed for general drilling tasks in ferrous and nonferrous metals when paired with the corresponding T-A holders and inserts.
