asme sa387 gr5cl1 steel plate ASME SA283/SA283M This grade of steel plate has a higher concentration of Chromium and Molybdenum, depending on the specific grade, which improves performance in the final industry application. SA387 Grade 11 Steel Plate Supplier - ASTM A387-11 Plates astm a387 gr5cl1 steel plate supplier. Benefits of SA 387 Grade