The TRT chimney nut is a fastener composed of two flaps in clip form. The design of this nut means that a double elastic force is exerted when tightened. In the middle of the upper flap there is a hollow cylinder or “chimney” with multiple threads which when given the correct torque guarantees maximum fastening and assembly strength. The lower flap incorporates a third flap which is set in the opposite direction to the outer flaps in order to ensure optimum grip on the panel. Depending on the assembly two types of thread are available: normal or self-locking. No special tools are required to mount chimney nuts, and they can be assembled much more quickly and easily than conventional nuts and costly operations such as tapping, welding or riveting can be avoided. They are normally mounted on the edge of a panel but can also be used in a rectangular mounting hole in the middle of a panel. The use of this nut allows slight adjustment within the mounting hole thereby ensuring correct alignment of the panels.