In various representative aspects, an assembly for securing a support bracket to rail guide used for mounting and installing solar panels is provided. More specifically, the assembly provides a novel and improved nut with a serrated surface in combination with a t-bolt with a serrated surface that is capable of penetrating the respective oxidation surface layers of the bracket and the rail guide when installed. When installed, provides a mechanism for using the bracket to connect the rail guide to a flashing that is typically installed on a roof. By employing the apparatus at various locations along the roof in a linear fashion, the rail support structure can be properly installed so that an array of solar panel modules to be installed.