ASTM A299/A299M specification covers manganese-silicon carbon steel plates for use in welded boilers and other pressure vessels. Plates under ASTM A299/A299M specification are produced in two grades. The steel shall be killed and shall conform to the fine austenitic grain size requirement. Tension test shall be made to conform to the requirements specified.ASTM A299/A299M standard main steel grade:ASTM A299/A299M Grade A,B(A299GRA,B).