Abstract: The present invention relates to a seat protector device of the type which may be employed with drill rods for transmission of thrust from a driving member to a driven member. More specifically, the invention relates to an improved drill rod system for earth drilling where the rod also provides an axial passageway for a fluid to carry drill cuttings away from the cutting area. The seat protector device of the present invention may be detachably inserted between one or more drill rod sections and/or between one of the drill rods and the drill bit and/or between one of the drill rod members and the driving chuck for transmitting thrust load forces while simultaneously reducing damage and/or wear between the component parts.