Drill America DWRRTPH series Qualtech High-Speed Steel taper pin reamer. This tapered reamer turns a straight hole into a tapered hole into which standard taper pins will fit. The straight-flute reamers are generally used by hand while the helical-flute is designed for machine use. The square on the shanks of the straight fluted are suitable for holding in a tap wrench or vise. The helical-flute taper pin reamer has the geometry for reaming holes for tapered pins with a machine. The free cutting action at high speeds produces a good finish and minimizes chip packing in the flutes. 0.0611-inches short end and 0.0806-inches large end.