An apparatus is provided for refining materials such as a tobacco material. The apparatus includes a disc assembly rotatably coupled to a drive arrangement. The disc assembly includes a disc body having first and second lateral surfaces each having a refining arrangement disposed thereon. First and second stationary refining arrangements are positioned in opposing relationship to the first and second lateral surfaces so as to form first and second refining zones. The disc assembly further includes first and second gear members. The first gear member is engaged with the drive arrangement, and the second gear member is engaged with the disc body. The first and second gear members are arranged to engage each other such that interaction therebetween rotatingly drives the disc body. The first and second gear members are configured to resist wear associated with interaction therebetween.