Carbide Hole Cutter, 1-3/8-Inch Klein Tools 31860 Cuts quick, precise holes in stainless steel, mild steel, iron, copper and brass sheet up to 3/16-Inch (5 mm) thick Split point pilot drill bit prevents bit walking Integrated flange prevents the operator from drilling beyond the sheet metal Conduit and pipe sizes: 1-Inch (25 mm) Uses replacement pilot bit 31874