A device for mounting magnetic discs (1) on a spindle (4) of a magnetic disc file assembly has a disc transfer mechanism provided with a disc supporting surface (2A) operative to support a disc (1) in non-contacting and relatively movable relationship with a fluid film formed therebetween. The thus supported disc (1) is axialy aligned, by a positioning mechanism (3), with the spindle (4) and then released into engagement with the spindle. The floating support of the disc (1) allows the disc to be moved relative to the disc supporting surface (2A) first into alignment and then into engagement with the spindle (4) without any mechanical contact and friction between the disc supporting surface (2A) and the disc (1) to thereby prevent the production of dusty matters otherwise produced by mechanical contact between the disc and the supporting surface.
