Double Coned Reamers consist of tool shank and a detachable reamer head, which provide the shank at one end engaged by the spindle of a machine tool and at the other with a sleeve defining a conical socket. Its head has an integral conical butt for engagement in the shank socket. Flute placement, relief and angle are designed to give the best results on all types of barrel steel. The long forcing cone created to give optimum results in any length chamber. The hex-drive permits use of a socket and T-handle when tap handles will not operate. These are also useful in removing gutta-percha in preparation for creating post space.