... Dipped Galvanized, Electro Galvanized, Natural finished, Chemical blackThreadsDIN, BS, NPT, Metric, BSPT, BSP, NPS (ISO7/1, DIN 2999, ... standard, American standard and DIN standard Kinds of screwed half coupling: bends, elbows ,tees, crosses, sockets, caps, backnuts, ... ,stainless steel ,alloy steel . Surface of screwed half coupling: cold galvanizing,hot galvanizing,and black Egdes: banded, beaded ...