An aluminum ingot casting machine comprising a source of molten metal, a rotatable annular ring, carrying ingot casting moulds and a drive means for indexing the moulds. The machine includes a vacuum demoulder having a vacuum seal arrangement comprising a sealing element having a flexible core which can deform to form a vacuum seal against an ingot and a flexible abrasion resistant outer layer on said core, and retaining elements located on a lower face of the vacuum lifting head for releasably retaining the sealing element onto the lifting head. The vacuum seal comprises a flexible ring shaped body, being rounded in cross section, having a fiber cord core and an abrasion resistant flexible sheathing surrounding the core.