... Place of Origin: China API stainlees carbon Steel Pipe Fittings ———————————————————————————————————————— Features—————————————————————————————————————————————GRADE: J55, K55, N80 ... (casing coupling).SURFACE TREATMENT: Whole phosphating, or inside phosphating and outside coatingPACKING: By carton, wooden case ... coupling, pup joint, reducer union, drill pipe coupling and also can process the special ...