Left Hand Expansion Reamer, Diameter: 1-15/16 in. Decimal Equivalent: 1.9375, Flute Length: 5 in., O.A.L.: 12-3/8 inch, Flute Type: Straight Flute, High Speed Steel. These reamers are used to enlarge holes by a few thousandths. The pilots and guides of these reamers are ground under size to allow smooth entance. The spiral flute style is especially suited for use in holes where the cut is interrupted by a longitudinal slot or keyway.