The relief cut removes some of the rigidity of a one-piece clamping collar to allow the screws to clamp more evenly and securely. A relief cut is important only on smaller bore collars because of the ratio of the screw to the collar material – the screw provides much of the clamp load. Climax puts a relief cut in collars with a 1 ½” bore or smaller. Relief cuts can be found on metric collars 19 mm and smaller and on our threaded collars sizes under 1 ¾-16 in.