3/8" Threaded Cobalt Drill Bit Standard 1/4-28 Thread
New- USA Made Length= 1-1/4" Diameter= .375"
Type "D" adapter drills are made from M42 8% cobalt high speed steel and are manufactured to NAS 965 Type "D" specifications with 135° heavy duty split points and surface treated for drilling hard, tough high tensile strength materials. When drilling low tensile strength materials, the Type "D" cobalt drill will have a significantly greater tool life than the NAS 965 Type "B", high speed steel adapter drill, resulting in a much lower cost per drill.