Sets - Extensions, Drill Bits & Screwdriver Bits

TightFit® threaded shank drill bits comply with National Aerospace Standards. The Standard provides the following description, “A special short flute, heavy duty drill designed for drilling the hard, high strength alloys used in aircraft manufacturing.” The drill bits are made from M2 or M7 high speed tool steel with self-centering, 135 degree, P3 split points and a Rockwell C scale hardness of 63.5 to 66. They are manufactured as right-hand tools with 5/16″ hex wrench flats and 1/4-28 UNF-2A threads. TightFit® threaded shank drill bits are concentric, self-tightening, non-slipping, long life tools designed for work in limited space situations.