A flange is a ridge which can either be external or internal. Flanges are used on the end of a pipe, steam cylinder, on the camera’s lens mount or for flange of a rail car. Flanged wheels are wheels with a flange on one side to keep the wheels from running off the rails. Flange is also used for a kind of tool used to form flanges. A flange can also be a plate or ring to form a rim at the end of a pipe when fastened to the pipe, such as a closet flange.