... :320 360 410 460 490 Carbon and carbon-manganese steel seamless pipe for ship-----American Petroleum Institute:Certificate of Authority to use the ... , GB6479-86, GB9948-88,GB3088-82, GB17396-98,DIN17195-79, ST45.8-III, YB235-70, YB528-65, GB5312-85, API5CT, ASTMA53B ... JISG3448. our products are made of 10#, 20#, 35#, 45#, ST45, ST55, CK45, Q235 (B, C, D, E), Q345 (B, C ...