Abstract: A flywheel (100) comprising a plurality of discs (102) arranged in a stack (104), including at least first and second end discs at either end of the stack (104), each of the plurality of discs (102) including a plurality of disc apertures (102a) therethrough, first and second plate members (106) disposed at opposing ends of the stack (104), one or both of the first and second plate members (106) including a plurality of plate apertures (106a) therethrough for alignment with the plurality of disc apertures (102a) in the first and second end discs respectively, connection means (114) for clamping the first and second plate members (106) together about the stack (104) of discs (102), the connection means (114) extending through each of the plurality of disc apertures (102a) without contacting the plurality of discs (102).