Stainless Steel 304 - Alloy Composition

Stainless steel type 304 is part of a family of stainless steel alloys (301, 302, 303, 304, 316, 347). Non-magnetic alloy 304 is the most versatile and the most widely used of all stainless steels, and has lower carbon content to minimize carbide precipitation and is used in high-temperature applications. It's commonly used to process equipment in the mining, chemical, cryogenic, food, dairy and pharmaceutical industries. Its resistance to corrosive acids.

Nominal Composition in Percent:

            Ni                     9.25

            Cr                    19.00

            Fe                  Balance

            Si                    1.00

            Mn                   2.00

            C                     0.080

            P                     0.045

            S                     0.030

UNS Number:


Other Standard Specifications:

AMS 5513, ASTM A313, ASTM A580, MIL-S-5059D 

300 Series—austenitic chromium-nickel alloys

  • Type 301—highly ductile, for formed products. Also hardens rapidly during mechanical working. Good weldability. Better wear resistance and fatigue strength than 304.
  • Type 302—same corrosion resistance as 304, with slightly higher strength due to added carbon.
  • Type 303—free machining version of 304 via addition of sulfur and phosphorus. Also referred to as "A1" in accordance with ISO 3506.
  • Type 304—the most common grade; the classic 18/8 (18% chromium, 8% nickel) stainless steel. Outside of the US it is commonly known as "A2 stainless steel", in accordance with ISO 3506 (not to be confused with A2 tool steel).
  • Type 316—the second most common grade (after 304); for food and surgical stainless steel uses; alloy addition of molybdenum prevents specific forms of corrosion. It is also known as marine grade stainless steel due to its increased resistance to chloride corrosion compared to type 304. 316 is often used for building nuclear reprocessing plants.


8.03 g/cm3 (0.290 lbs/in2)

Exceptional Properties:

Durability, toughness, corrosion resistance