A disk clamp for securing a data storage disk to the hub of a spindle motor in a disk drive prevents the migration of lubricant into sensitive areas of the disk drive. The problem of lubrication migration due to the use and presence of fastener lubricant is resolved by using a rib on a composite disk clamp. The rib strengthens the clamp structure and has a sealing ring. The ring has a semi-circular sectional profile with a flat surface that is used to bond the ring to the rib. The ring has elastic properties that compensate for hub vibration to isolate the disk clamp from the hub, and also provides damping between the hub and the disk clamp.