Abstract: This invention relates generally to a flexible fastener for coupling members. In a preferred embodiment, the flexible fastener may be used to couple members that are non-parallel, non-aligned, or in specific instances when selective compliance in a member is desired. The present invention is directed generally to a fastener that comprises a spiral set of teeth. The spiral set of teeth are configured to allow a nut to travel along at least a portion of the spiral set of teeth. A selectively compliant core material runs completely internally to the spiral set of teeth, so that the fastener is laterally flexible along a length of the fastener. The selectively compliant core material is connected to the spiral set of teeth.