arrangement through the hollow of the rung 16 the diameter of shaft 32 being slightly less than that of hollow of the rung such that there is frictional engagement therein the length of shaft 32 being slightly in excess of the width of the ladder 10 from side rail 12 to side rail 14 the shaft 32 can define an elongated threaded rod or screw the head 36 being of a greater diameter than that of the hollow such that it does not slide thereinto if desired a slotted head can be provided or a winged head etc once the shaft 32 has exited from the opposite end of the rung 16 and rail 12 a nut 38 engages the threaded end 34 to secure the same in the solid rung ladder embodiment the apparatus of fig5 is saddled or caps the side rail 12 in a position such that the rung 16 is disposed in the area 40 between the parallel rows of vertically disposed apertures 28 30 suitable converting and engaging means such as a u shaped clamp 40 having threaded end portions 42 44 and a movable collar or median connecting portion 43 and nuts 46 therefor engages a pair of horizontally disposed apertures.