For 304 stainless steel, the Ni element in its composition is very important, directly determines the corrosion resistance of 304 stainless steel and its value.

The most important elements in 304 are Ni and Cr, but they are not limited to them. Specific requirements are specified in the product standard. The common determination of the industry that as long as the Ni content is greater than 8%, Cr content is greater than 18%, can be considered 304 stainless steel. This is why the industry will call this type of stainless steel 18/8 stainless steel. In fact, the relevant product standards for 304 have very clear provisions, and these product standards for different shapes of stainless steel and some differences. Below are some common product standards and tests.

To determine whether a material is 304 stainless steel, must meet the requirements of every element in the product standards, as long as there is a does not meet, it can not be called 304 stainless steel.

1,ASTM A276(Standard Specification for Stainless Steel Bars棒材 and Shapes型材)

2,ASTM A240(Chromium and Chromium-Nickel Stainless Steel Plate板材,Sheet片材, and Strip带材 for Pressure essels and for General Applications)