Disclosed herein are various exemplary embodiments of shielding enclosures. In an exemplary embodiment, a shielding enclosure generally includes a frame and a lid. The frame includes vertically extending sidewalls and horizontally inwardly extending lateral flanges therefrom. The lateral flanges define a top opening of the frame and include outwardly extending detent legs. The lid includes a top portion for covering the top opening of the frame. The lid also includes flanges downwardly extending from edges of the top portion. At least one of the flanges has a detent structure, such that when the lid is installed on the frame the detent legs of the frame are engaged by the detent structure. The detent structure may, for example, be detent slots or detent protrusions.