In various representative aspects, an apparatus for clamping and grounding solar panel frames to a mounting rail is disclosed herein. The apparatus comprises a fastener with an enlarged end, and a shank, with the enlarged end having one or more sharp protrusions that resemble teeth, and a washer with one or more sharp protrusions, and an opening. When installed, the shank is inserted through the opening of the washer, the sharp protrusions of the enlarged end penetrate either the lower or upper surface of the mounting rail and the sharp protrusions of the washer penetrate the other surface of the solar panel frames while at the same time creating a grounding path through the apparatus.