a structure for firmly combining cables with a clamping element is disclosed . the clamping element is of tubular - like shape and has a circular , c - shaped , 6 - shaped or h - shaped section , and the improvement includes the clamping element having locking ribs on an outer surface thereof or locking grooves on an inner surface thereof . when the clamping element is used to crimp cables , it can be firmly combined with the cables due to the locking ribs or locking grooves , thereby being able to reduce electrical resistance and temperature rise , and to enhance tensile strength and quality in connecting region of the cables .