Stainless Steel 304 Bar In metallurgy, stainless steel,[also known as inox steel or inox from French inoxydable (inoxidizable), is a steel alloy, with a minimum of 10.5% chromium content by mass and a maximum of 1.2% carbon by mass.Stainless steels are most notable for their corrosion resistance, which increases with increasing chromium content. Additions of molybdenum increase corrosion resistance in reducing acids and against pitting attack in chloride solutions.