304 stainless steel hexagon bar is a type of stainless steel bar that has six sides and a hexagonal cross-section. It is made from the 304 stainless steel alloy, which contains chromium, nickel, and sometimes small amounts of other elements like molybdenum and nitrogen. 304 stainless steel is an austenitic steel and is one of the most widely used stainless steel alloys due to its excellent corrosion resistance, good strength, and ease of fabrication. Diameter is measured across flats.