Zinc Grounding Clamp for Bare Wire and Pipe, 25 PackDescription Zinc Grounding Clamp for Bare Wire and Pipe Size 1 2 to 1 in. 1 2 in to 1 in ground clamps are used to ground bare copper or aluminum wires to water pipes, ground rods, rebar or other structural members that will ensure positive grounding to the earth. These clamps may be used on pipe sizes 1 2 in to 1 in and are made to accommodate bare cable. Primus Cables unique labor saving design allows the upper portion of clamps to slide open easily