Reamer with unequally spaced flutes

摘要

A reamer for making a tapered hole is disclosed. The reamer comprises a cylindrical forward portion joined to the front end of a conical rear portion, the rear portion tapering outwardly from its front end. The forward and rear portions have co-incident longitudinal axes and at least three cutting flutes extending continously on the forward and rear portions and which are unequally spaced about the longitudinal axes. In one embodiment the flutes are either aligned with or helical about the longitudinal axes; and furthermore are misindexed about the axes and therefore are unequally spaced apart. In another embodiment the flutes have different helix angles about the longitudinal axis. In other embodiments the cylindrical forward portion is eliminated leaving only the conical rear portion making a reamer suitable for enlarging holes having existing tapers.