Drill America DWRRTP 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. This reamer is recommended for most materials. 0.2773-inches short end and 0.354-inches large end.