Drill America #21 Cobalt Long Threaded Shank Drill Bit Overall Length 2-1/8, TSD Series

Drill America tsd series stubby M42 cobalt steel drill bit. This Type "D" adapter drill is made from M42 8 percent cobalt high-speed steel and is manufactured to nas 965 Type "D" specifications. Featured with 135 Degrees heavy duty split point and surface treated for drilling hard, tough, high tensile strength materials. When drilling low tensile strength materials, this drill bit will have significantly greater tool life than the nas 965 Type "b", high-speed steel adapter drill, resulting in a much lower cost per hole.