Abstract: A tool for installing a spring rail fastener includes a main arm whose bottom end is provided with a toe adapted to fit over one of the angled axial ends of the fastener. The main arm is connected near its bottom end, above its toe and by way of a hinge having a transverse pin, to a secondary arm. The secondary arm includes a short first length adapted to be inserted into the housing of an anchoring insert, a second length forming a U-shape bent through 180.degree., a third length that is substantially parallel to the first length and on which the hinge is mounted, and a fourth length extending outwardly and downwardly in inclined manner relative to the third length and terminating in a curved zone.