A cassette intended to be provided on a rolling mill, the cassette (1) forming a self-supporting unit including: a roller intended to constitute one of the two intermediate rollers of the rolling mill; two chocks (3) whereon are mounted the ends of the roller (2); at least one support arm (4) of the at least one side bearing member the support arm extending between the two chocks and being mounted pivotingly in relation thereto. The cassette includes at least one pair of support elements (5) receiving the ends of a rotating shaft (6) of the at least one support arm and the two support elements being detachably fastened, respectively, on the two chocks so as to allow the disassembly of the at least one support arm of the chocks and/or the assembly of the at least one support arm on the chocks independently of the disassembly/assembly of the roller.