The Difference Between 304 and 316 Stainless Steel

When selecting a stainless steel that must withstand a corrosive environment, austenitic stainless steels are usually used. Austenitic stainless steels contain high levels of nickel and chromium and have excellent mechanical properties, as well as excellent corrosion resistance. In addition, many austenitic stainless steels can be welded and formed.
The two common grades of austenitic stainless steel are 304 and 316 and to help you determine which grade is right for your project, this blog will look at the differences between 304 and 316 stainless steel.

304 Stainless Steel

Grade 304 stainless steel is often considered the most common austenitic stainless steel. It contains a high nickel content, typically between 8% and 10.5% by weight, and a high chromium content of around 18% to 20% by weight. Other major alloying elements include manganese, silicon and carbon. The remaining chemical composition is mainly iron.The density of 304 stainless steel is 7.93g/㎝.
The high chromium and nickel content gives 304 stainless steel its excellent corrosion resistance. common applications for 304 stainless steel include:
Appliances such as refrigerators and dishwashers
Commercial food processing equipment
Fasteners
Piping
Heat exchangers
Structures in the environment will corrode standard carbon steel.

Similar to 304, grade 316 stainless steel contains high levels of chromium and nickel. 316 also contains silicon, manganese and carbon, most of which is composed of iron. the main difference between 304 and 316 stainless steel is the chemical composition, where 316 contains high levels of molybdenum; typically 2% to 3% by weight, whereas only traces of molybdenum are found in 304. The higher molybdenum content results in the higher corrosion resistance of grade 316.The density of 316 stainless steel is 7.98g/㎝.
When selecting an austenitic stainless steel for marine applications, 316 stainless steel is often considered one of the most suitable choices. other common applications for 316 stainless steel include:
Chemical processing and storage equipment.
Oil refinery equipment
Medical equipment
Marine environments, particularly where chlorides are present
Food industry

With the naked eye 304 and 316 stainless steel words, generally do not see any difference, so many businesses for their own benefit, the 304 stainless steel as 316 to sell, but the price difference between the two is still quite large, because 316 belongs to the food grade, corrosion resistance is better, so the price of 316 will be more expensive than 304 some.If you spend the money on 316 and get back 304 stainless steel cutlery, you’ve wasted your money.
Because 304 and 316 added chemical composition is different, so in distinguishing between the two, you can also use professional stainless steel potion to distinguish. After dropping on the stainless steel potion, 304 material surface is generally normal hair a little red, while 316 material will be black.
If there is no professional potion, you can also use a magnet to test the distinction, if the stainless steel belongs to 304 material, it can not be sucked by a magnet. But the accuracy of this method is relatively low.
In fact, if only for domestic use, it is not necessary to choose 316 material, because the characteristics of 304 is also in full compliance with domestic standards, so you can also avoid the price of 316 material only to buy 304 products.

The following are some situations where 304 stainless steel may be a better choice.
The application requires good formability. the higher molybdenum content in grade 316 may have an adverse effect on formability.
There are cost issues with the application. 304 grade is usually more affordable than 316 grade.
The following are some of the situations where 316 stainless steel may be a better choice.
The environment contains high levels of corrosive elements.
The material will be placed underwater or exposed to water at all times.
In applications where greater strength and hardness is required.