Pipe (as per IS ;- 1239,m Part-1, 1990 of reputed Make by 2mm thickness baclass galvonized iron pipe & 3.0 mtrs length tapered finished smooth at one end for a length of 75 mm & Clamp at the other end. ... The GI Earthing Clamp/ Strip (C- Clamp Type) is to be of 50mm width, 6mm thickness & flange length of 65 mm in each side.