ISO & API cerficated, 1st Reliable Pipe Manufacturer In China, 2 year quality warranty. Hot dipped/Electro Galvanized/Black Standard ASTM A 53, BS1387, API or DIN standard. Material: A 106 Gr. B, A 53 Gr. A/Gr B, API 5L Gr. B.Size: 1/2" to 24" Bigger size also available above 24", in DSAWPAINTING: Hot dipped, Electro. Gal., Black. For catalog, pls visit www.hebei-longsheng.com