Different numbers indicate different magnesium content of magnesium ingots: 1 magnesium ingot Mg not less than 99.95%, 2 magnesium ingots Mg not less than 99.92%, 3 magnesium ingots Mg not less than 99.85%. But this is the old standard, new The standard is not like this, and it is directly replaced by grades: magnesium ingots are divided into six grades according to their chemical composition: Mg9999, Mg9998, Mg9995A, Mg9995B, Mg9990, Mg9980.