Abstract: The invention relates to well reamer for borehole reaming within a specified interval. The well reamer has a housing with inclined slots, radial holes and a central straight-through channel, in which a spring-loaded rod with holes in the upper and lower parts is located. The upper holes of the rod are covered when the operating elements are extended into an operating position. A plurality of legs, including cutters rotatably supported on the legs, are moved by pistons between an operating position and a transport position along the inclined slots. Free-ends of the pistons may be connected to the rod by sliders, which are movable radially into openings in the rod to connect the rod to the pistons to move the rod with the legs.