API steel pipe follows the standards like ASME B36.10, API 5L, ASTM A106 and ASTM A53 Grade B, etc. Our API steel pipes come into seamless pipes and welded pipes, and are widely used in many industries, such as petroleum, power generation, natural gas, chemicals, shipbuilding, papermaking, and metallurgy, etc. SizeSeamless Pipe: 1/2\" ~24\", DN15~DN600, OD. 21.3MM~609.6MMWelded Pipe: 1/2\" ~48\", DN15~DN1200, OD. 21.3MM~1219.2MMMaterialsCarbon steel: ASTM/ASME A234 WPB-WPC, ST37,Alloy steel: ST52, 12CrMo, 15CrMo, WP 1-WP 12 , WP 11-WP 22 , WP 5-WP 91-WP 911Industrial Processeshot rolled, hot expanded, cold drawn.