Quality standard: Gb/t 8163: seamless steel tubes for liquid service Gb 3087: seamless steel tubes for low and medium pressure Gb 5310: seamless steel tubes and pipes for high pressure boiler Astm a106: standard specification for seamless carbon steel pipe for high-temperature service Astm a179: standard specification for seamless cold-drawn low-carbon steel heat-exchanger and condenser tubes Astm a192: standard specification for seamless carbon steel boiler tubes for high-pressure service Astm a333: standard specification for seamless and welded steel pipe for low-temperature service Astm a335: standard specification for seamless ferritic alloy-steel pipe for high-temperature service Jis g3452: carbon steel pipes for ordinary piping Jis g3454: carbon steel pipes for pressure service Bs 3059: steel boiler and superheater tubes Din 1629: seamless circular tubes of non alloy steels with special quality requirements Din 17175: seamless steel tubes for elevated temperatures Api 5l: line pipe Size: Outer diameter: hot finish: 2" - 30", cold drawn: 0.875" - 18" Wall thickness: hot finish: 0.250" - 4.00", cold drawn: 0.035" - 0.875" Length: random length, fixed length, srl, drl Heat treatment: annealed, normalized Surface: zinc coating, black phosphated, oiled.