A ground clamp having a clamping strap formed of a corrosive-resisting material with a series of uniformly sized and spaced apertures to facilitate the installation of the clamping strap and clamp onto a wide range of pipe, rod or conduit diameters. A tightening stud, through which the clamping strap is secured about the object to be grounded, includes a terminal portion having a slot therein to receive and have secured thereto one or more terminated ground wires. A pair of curved plates are adjustably positionable along the stud to form a tight clamping action of the clamping strap about the object to be grounded without subjecting the strap to localized stresses or damage. An abrading sleeve is carried by the clamping strap, and positioned thereon to engage the outer surface of the pipe, rod or conduit to be grounded. As the tightening stud tightens the clamping strap about the object to be grounded, a plurality of abrading points, formed on the abrasive sleeve, engage the object to be grounded to cut or scrape through the outer surface thereof as the clamping strap is tightened to ensure a proper electrical contact between the grounding clamp and the object to be grounded.