As others have said this appears to be a beam clamp for hanging pipe. They clamp onto the bottom flange of a Wide Flange Beam or an I Beam. ITT Grinnell and Anvil catalogs are on line with similar clamps. The heavy duty beam clamps from Anvil can use up to 3/4" diameter threaded rods and hold up to 1600 lbs. I have not seen one with the hanger rod off set to the side but this may be an older version or special application.