Abstract: A magnetic tape cassette comprises a cassette casing housing a pair of tape reel assemblies around which a magnetic tape is wound. Each tape reel assembly comprises a reel hub and a center core. The reel hub is associated with the central core so as to be free to move independently of the central core in a direction parallel to the rotational axis of the tape reel assembly. This allows axial movement of the central core for engagement with a reel shaft during thrust-loading. The reel line hub is, in turn, associated tape. By allowing the reel hub to float axially relative to the center core, and hence relative to the reel drive shaft, the reel hub to float axially relative to the central shaft, axial movement of the central core ensures that the reel hub will not apply stress to the tape during loading.