Abstract: An improved assembly (12) for use in a ringbinder (10) to hold sheets (P) paper having holes (H) punched in them. A prong bar assembly (16) includes first and second spaced apart and aligned U-shaped members (18a, 18b) attached to respective end pieces (L1, L2) forming outer leaves of the binder. These members have respective upper and lower flanges (40u, 40l) to strengthen the members and make the ringbinder sturdier. First and second swivel locks (26a, 28a) are located at each end of the prong bar assembly. Each lock includes a pair of L-shaped links (26b, 26c, 28b, 28c) having one end pivotally attached to one of the U=-shaped members, with the other ends (46) being pivotally connected together. The swivel locks are movable from a prong bar assembly locking position to an unlocking position, this enabling the U-shaped members to move relative to each other. A pair of curved sheet holding prongs (22a, 22b) each have one end (34) stakingly attached to the respective U-shaped members.