Abstract: A device for the installation, on a projecting border (6) of an automobile body frame, of a profile (5a) having a U-shaped cross section including a metal reinforcement jacketed with a resilient material, this device comprising a mallet having a flexible head (4), means (3) for impressing an alternating percussion movement on the head of this mallet and at least one system for guiding the profile (5) capable of bringing the latter in front of that portion of the flexible head (4) of the mallet intended to act on it, this guide system comprising a structure having a U-shaped contour, between the branches (8) of which the profile (5) can be engaged and which can be closed by a movable element capable of substantially joining together the branches (8) of the structure in order to maintain the profile therein.