Abstract: A material transfer system is disclosed using a hollow cylindrical lock shaft for rewinding flexible material from an original core to at least one transfer core. The shaft has an interior and exterior wall, a length, and at least one curved locking base recessed along the length. The bases have a first and second wall with a floor having a progressively decreasing radius from the first to the second wall. Multiple legs extend radially inwardly from the interior wall and have gripping feet are at their distal ends. A plurality of locking ribs extend the length of the locking bases and are affixed to the floor at the each end of the rib. The locking ribs have a diameter sufficient to enable the locking rib outer circumference to extend beyond the circumference of the shaft exterior. At least one locking strip is affixed to at least a portion of the shaft's length, extending beyond the circumference of the exterior wall to prevent the cores from moving freely.