ASTM A738 Grade B is a kind of C-Mn-Si steel plates material used to fabric middle or low temperature pressure vessels. Obviously, A738 is divided into three grades or levels :A738 Gr. A, A738 Gr. B, A738 Gr. C . In order to meet the property requirement of ASTM A-738/A-738M standard, this material must be done heat-treatment. jwvivian98 (at) yahoo (dot) com Skype jw-vivian (at) hotmail (dot) com Standard: ASTM A738/A738M Thickness :3mm -500mm Width :1000mm-4000mm Length ;1000mm-18000mm