A self-tightening device for fastening two structures together includes a female component and a male component where the female component is capable of receiving the male component. The female component includes a moveable member, an energy storing mechanism and a retaining mechanism. The movable member is movable between an unlocked position and a locked position. The energy storing mechanism has stored energy for causing the moveable member to move from the unlocked to locked position when the energy in the energy-storing mechanism is released. The retaining mechanism holds the energy-storing mechanism in the stored-energy state until the retaining mechanism is released. Upon the release of the retaining mechanism, the energy storing mechanism is actuated from the stored-energy state to the released-energy state causing the movable member to move from the unlocked position to the locked position engaging the male component with the female component when the male component is inserted within the female component.