FLANGE A flange is a protruded ridge, lip or rim, either external or internal, that serves to increase strength (as the flange of an iron beam such as an I-beam or a T-beam); for easy attachment/transfer of contact force with another object (as the flange on the end of a pipe, steam cylinder, etc., or on the lens mount of a camera); or for stabilizing and guiding the movements of a machine or its parts (as the inside flange of a rail car or tram wheel, which keep the wheels from running off the rails). Flanges are often attached using bolts in the pattern of a bolt circle
ACRYLIC A display case may be freestanding on the floor, or built-in (usually a custom installation). Built-in displays may be mounted on the wall, may act as room partitions, or may be hung from the ceiling. On occasion, display cases are built into the floor, such as at the Museum of Sydney (in Sydney, Australia), where the remains of drains and privies are shown in their original context, along with other archeological artifacts.