304 vs 316 Stainless Steel
Stainless is a term coined early in the development of these steels for cutlery applications. It was adopted as a generic name for these steels and now covers a wide range of steel types and grades for corrosion or oxidation resistant applications.
Stainless steels are iron alloys with a minimum of 10.5% chromium. Other alloying elements are added to enhance their structure and properties such as formability, strength and cryogenic toughness. These include metals such as: Nickel, Molybdenum, Titanium, Copper. Non-metal additions are also made, the main ones being: Carbon, Nitrogen.
Stainless steel 304 and 316 are the most widely used types of stainless steel. It can be difficult to visually, and sometimes characteristically, tell the difference between the two types of steel. So, what is the difference?
The biggest difference in the types of steel is the presence of molybdenum in stainless 316. Molybdenum is a metallic element, especially used for the strengthening and hardening of steel. The most common make up of stainless 316 is 16% chromium, 10% nickel, and 2% molybdenum – whereas stainless 304 is typically 18% chromium and 8% nickel. The molybdenum is added to stainless 316 to help resist corrosion to chlorides.
304 Stainless Steel
also known by many as A2 stainless, is the most common form of stainless steel used around the world, largely due to its excellent corrosion resistance and value. It contains between 16 and 24 percent chromium and up to 35 percent nickel, as well as small amounts of carbon and manganese.
304 can withstand corrosion from most oxidizing acids. That durability makes 304 easy to sanitize, and therefore ideal for kitchen and food applications. It is also common in buildings, décor, and site furnishings.
304 stainless steel does have one weakness: it is susceptible to corrosion from chloride solutions. Chloride ions can create localized areas of corrosion, called “pitting,” which can spread beneath protective chromium barriers to compromise internal structures. Solutions with as little as 25 ppm of sodium chloride can begin to have a corrosive effect.
316 Stainless Steel
also known as marine grade stainless or A4 stainless, is well-known for its increased resistance to corrosion and its superb abilities in salt-water and marine applications. While it comes with the same physical properties as 304 as well as similar utilitarian functions, the key difference is that 316 stainless steel incorporates about 2 to 3 percent molybdenum. The addition increases corrosion resistance, particularly against chlorides and other industrial solvents.
316 stainless steel is widely used whenever chemical process and high-salinity environments warrant chloride-resistant features and due to its non-reactive traits, is also used in the manufacture of medical surgical instruments.
CHOOSING 304 OR 316 STAINLESS
Stainless steel’s resistance to corrosion and staining, low maintenance, and familiar lustre make it an ideal material for many applications. China LG Supply carries a full assortment of stainless steels ranging from 304 and 316, as well as other grades and finishes.
The slightly higher price point of 316 is well worth it in areas with high chloride exposure, especially the coast and heavily salted roadways. If you’re looking for a durable alloy and superior corrosion resistance isn’t necessary, 304 stainless can work perfectly.
China LG Supply offer a wide range of stainless steel products, including eye bolts & nuts, eye plates, eye strap & angles, hooks & clips, pulleys, rings, thimbles, shackles, swivels, terminals, turnbuckles, u bolts, and wire rope clips.