Abstract: A floating type brake disc assembly has a hub and an annular disc which is concentrically disposed around the hub. The hub and the disc have plural sets of connecting dents each set being opposingly provided in a connecting portion of the hub and the disc. A hollow pin which has a flange on one end is inserted into each set of the connecting dents such that the hub and the disc are connected together while allowing for a slight floating movement between the two members. The hollow pin has a thick-wall tube portion which lies next to the flange and is adapted to be inserted into each set of the connecting dents and a thin-wall tube portion which has an outer diameter smaller than that of the thick-wall tube portion and is provided next to the thick-wall portion away from the flange.