Chicago-Latrobe Screw Drill, General Purpose, Series: 157L, Imperial, #20 Drill - Wire, 0.161 in Drill - Decimal, 2-1/8 in Overall Length, 3XD Depth of Cut, 2 Flutes, Left Hand Spiral Flute, 1-1/16 in Flute Length, 0.161 in Dia x 1.0625 in L Shank, Straight Shank, 118 Degree Point, Radial Point, Left Hand Cutting Direction, HSS Cutting Edge, HSS, Bright, Applicable Materials: Carbon steel, mild steel, non-ferrous materials, aluminum, magnesium, copper, wood, slate and some thermoplastics