Abstract: A method and structure for joining two elongate objects together end-to-end includes a first object having an end formed with an annular groove, a second object having an end formed with an annular ridge dimensioned to fit snugly in the annular groove of the first object, and a double-ended screw, one end of which is screwed into the first object at a point spaced equally from the various circumferential sections of the group, and the other end of which is screwed into the second object at a point spaced equally from the various circumferential sections of the ridge to thereby join and hold the first and second objects together with the ridge fitted in the groove.

Abstract: A dowel system for securing in a generally abutting relationship two parts or pieces of material having facing surfaces and preformed, aligned annular recesses. The dowel system includes a tubular body having sidewalls which are thinner near the middle of the body than at the ends thereof. The tubular body is dimensioned so that opposite ends thereof may be inserted into respective annular recesses of the two pieces of material, with enough room being left around the sides of the tubular body to allow adhesive to be put in place in the annular recesses to join the tubular body to the sidewalls of the annular recesses.

Abstract: A jig used for precision boring of holes in a working surface of an elongate work piece includes a pair of mounting plates and an elongate connecting member for mounting the plates together in adjustable, spaced positions such that the plates face each other and can be moved in a direction toward and away from each other. Engagement pad members are attached to mutually respective, bottom sides of the pair of plates. The pad members are adapted to engage opposite sides of a work piece in firm engagement therebetween when the pair of plates are moved toward each other, with the work piece being disengaged when the pair of plates are moved away from each other. A guide member is mounted between the pair of plates and is adapted to guide a boring tool in a linear movement toward and away from a working face of the work piece. The guide member is mounted and positioned such that the linear movement of the boring tool lies in a plane passing generally through the longitudinal axis of the work piece.