Lifting eye screws are to be screwed down hard against the substrate. When two lifting eye screws are used, their interrelated position must be such that the eyes lie on the same plane. As they must be tightened firmly against the substrate, it may be necessary to place washers between the flange and the substrate to ensure the eyes are on the same plane. Angles greater than 90º between the lifting slings are not permitted. Installation must not be carried out against a plane that significantly deviates from a plane perpendicular to the lifting direction straight up. Max. permitted load only applies for lifting eyes designed according to the given standard and if installation is performed as set out above.