A device for osteosynthesis includes a body having a proximal surface, a distal surface configured and dimensioned to face a target portion of bone over which the body is to be mounted and a through opening extending through the body from the proximal surface to the distal surface along a central axis. The through hole includes a first protrusion extending from an inner surface thereof toward the central axis. The first protrusion is biased toward an unstressed state in which the first protrusion extends into the through opening to a first distance from the central axis. The first protrusion is movable toward the inner surface when subjected to a force directed outward from the central axis.