A retaining bar to be used in combination with a heat furnace supporting assembly for supporting at least one receptacle. The retaining bar comprises at least one single piece elongated body having a finite length and at least one receptacle receiving cavity defined therein and extending along a section of the length of the body. Each one of the at least one receptacle receiving cavity is configured to receive therein one of a bottom section and an upper section of one of the at least one receptacle. A heat furnace receptacle supporting assembly comprising such a retaining bar and a heat furnace provided with the heat furnace receptacle supporting assembly are further provided.