A self-locking forkbolt uses an absolute minimum of components, comprising only a latch pivoted near a pin receiving slot in the flat surface of a structural member, with no need for a separate biasing spring to hold the latch closed across the slot and trap the pin. Instead of a separate spring, the latch is formed of an inherently resilient material that is pushed slightly away from the flat surface to which it is pivoted, in all positions but the fully closed position of the latch, by an integral tab. At the fully closed position of the latch, the tab snaps into a retention hole, to firmly lock the latch in its closed position to trap the pin in the slot.