Bisco Tool Supply has for sale 3 Flats Drill Bits 1-3/8" with a 1/2" reduced shank. These drill bits are High Speed Steel. These Flatted Drill Bits are 6" OAL and have 3" of Flute Length. 3 Flatted or 3 Flats Drill Bits are made for better gripping and these drills have surface treated flutes with a reduced flatted shank. 3 Flats drill bits expand the size range capacity of a portable drill chuck. Common Flute and overall length for minimal adjustment during tool changes. Precision ground for high degree of concentricity between shank and body diameter. 3 Flats Drill Bits are ideal for drilling in low and medium tensile strengh materials. Call Bisco Tool Supply Toll Free 1-866-247-2635 for drill bit questions.