A socket assembly includes a socket having a mounting hole which includes a plurality of insides and yield recesses located alternatively between the insides. A control member is rotatably mounted to the socket and has a through hole, a plurality of stops extend inward from an inner periphery of the through hole. The stops are deformable when being applied with a force along the axis of the through hole. A polygonal object can be forced into the mounting hole by squeezing and bending the stops. After the object is loosened and received in the socket, the stops support the nut from dropping from the mounting hole. When the control member is rotated to off align the stops from the path that the corners of the polygonal object may drop, the object is easily take out from the socket.