The Flat spring nut is a fastener composed of two raised thread forms which give double elastic pressure. The bow of the base and the arched form of the thread forms mean that two different forces are applied gradually to the screw when tightened. Radial force A is produced by the pressure of the thread forms deep into the thread while axial force B is exerted upon the outside of the thread due to the compression of the thread forms onto the base. No special tools are required to mount this nut and it is quicker and easier to mount than conventional nuts.As it is self-locking, costly operations such as tapping, welding or riveting are avoided. It can also be used with fragile materials such as glass, plastic or enameled surfaces. In these cases the resilience of the nut avoids cracks or damage to the application area. This nut locks with tightening torques which much lower than for standard nuts due its great resilience.