Abstract: A slip lock pin and cap for fastening two or more objects together includes a pin having a body and insertable into aligned openings in the objects. The pin body has protruding locking ears on its ends which engage shoulders in the openings upon rotation of the pin through 90.degree. after insertion into the openings. A cap is then placed over each end of the pin body. The caps have protruding portions which extend into the openings on opposite sides of the pin body and prevent rotation of the locking ears to a position disengaged from the shoulders. The caps have a lip around an opening into which the pin ends extend, and the lip engages a groove in the pin to retain the cap on the pin. A thin walled section of the cap is movable into a recess in the pin end to help rotate the lip out of the groove and release the cap from the pin.