Floor panels are shown, which are provided with a mechanical locking system on long and short edges allowing installation with vertical snap folding that could be accomplished automatically without tools and where the short edge locking system has a tongue made in one piece with the panel. The floor panels may have a first and a second connector at the long edges that are configured to obtain a minimum of friction facilitating a displacement, by a spring back force from the bending of a short edge locking strip, of a new panel in a horizontal direction along the long edge during the vertical snap folding action.