Polygonal shafted stud with corner grooves

Claim 1

IN COMBINATION, A FASTENING DEVICE AND A PLATE-LIKE MEMBER, SAID FASTENING DEVICE COMPRISING AN ELONGATED STEM OF SLIGHTLY YIELDABLE MATERIAL HAVING A PLURALITY OF PLANAR SIDE FACES OF SUBSTANTIALLY LIKE WIDTH AND UNIFORMLY SITUATED ABOUT THE LONGITUDINAL AXIS OF THE STEM TO DEFINE A GENERALLY POLYGONAL CROSS-SECTION, EQUI-ANGULARLY SPACED RADII FROM THE AXIS OF THE STEM AT A POINT ON THE AXIS BEING PERPENDICULAR TO THE RESPECTIVE FACES AT LONGITUDINAL MEDIAL LINES OF THE FACES, THE STEM HAVING A LONGITUDINAL GROOVE AT EACH CORNER THEREOF BETWEEN THE FACES, THE SIDE WALLS OF THE GROOVE MEETING THEIR ADJACENT FACES AT LEAST IN ALTERNATE SEQUENCE AT AN ACUTE ANGLE, SAID PLATELIKE MEMBER BEING OF RELATIVELY NON-YIELDING MATERIAL AND HAVING A HOLE SLIGHTLY GREATER THAN OF SIMILAR GEOMETRIC SHAPE AS THE CROSS SECTION OF THE STEM, WITH PLANES OF THE FACES EXTENDED TO INTERSECTION, TO RECEIVE SAID STEM FREELY SLIDABLY THEREIN, THE SIZE OF THE HOLE BEING SMALL ENOUGH TO PREVENT TURNING OF THE STEM WITHIN THE HOLE WITHOUT DEFORMATION OF THE STEM, SO THAT WHEN THE STEM IS IN THE HOLE AND TURNED UNDER FORCE, THE MATERIAL OF THE STEM AT SIDE WALL OF THE GROOVE WILL YIELD AND BE FORCED INTO THE GROOVE IN THE ZONE OF THE PLATE-LIKE MEMBER AND LEAVE STEM EDGE PORTIONS FOR PROJECTING LATERALLY OVER AT LEAST THREE MARGINAL PORTIONS OF THE HOLE, THE STEM BEING OF GREATER LENGTH THAN THE THICKNESS OF THE PLATELIKE MEMBER SO THAT A PORTION OF THE STEM MAY EXTEND WELL THROUGH THE PLATE-LIKE MEMBER.