In an embodiment, a self-locking pin includes a cylindrical shaft having a slot at a front end, an enlarged head at the rear end of the shaft, first and second toggles mounted within the slot, a compressible biasing member mounted between the toggles, and a mounting pin extending through the shaft and the toggles. The mounting pin is fixed in position on the shaft and the toggles are movable relative to the mounting pin. Each toggle is movable from a first position in which the respective toggle extending outwardly from an open end of the slot to a second position in which each toggle is pushed inwardly into the slot. The biasing member is compressed when the toggles are in the second positions. A single toggle can also be provided.