Difference between 304 and 316 Stainless Steel

The stainless steels are used in most metal applications because of their strength, corrosion resistance and cost effectiveness. There are ferritic, austenitic and duplex stainless steels. The 304 and 316 steels are austenitic stainless steels. They are both 18% chromium and 8% nickel in the composition. The 316 material has molybdenum in the composition. The 4% molybdenum allows the 316 material to have high corrosion resistance against chloride ion. Both materials have carbon, iron, manganese, phosphorus, sulfur and silicon in the composition. They both have 8grams per centimeter cube densities. The 304 material is much easier to machine than the 316 material.

The 304 vs 316 stainless steel machinability is favorable for the 304 material. It could be formed and machined. It is easy to clean for strains. While the 316 is hard to machine and hard to clean it does not catch rust and other surface corrosion easily. These reasons serves differently in different applications. The regular domestic and low cost applications use 304 due to the cost efficiency and easy to clean features. The 316 is used in sea water, marine and food grade applications because of the high corrosion resistance. However, the 316 material is more expensive than the 304 due to the molybdenum addition in the content. The 316 material is also harder to form. So the use of 316 is preferred only in applications where the 304 cannot be used. However, 304 material can replace the 316 material wherever possible. The 304 316 stainless steel magnetic properties are similar but the 316 has less magnetic properties compared to the 304 material.

The magnetic property of these materials is mostly because of the magnetic properties of nickel in the composition. Both these materials can be subject to particle separation in the face of powerful magnetic separators in the process flow systems. These cause the materials to disintegrate into small particles which could be attracted towards the magnetic field. The use of 316 material instead of the 304 material in high corrosive and food grade production systems reduce the risk of the particle attraction happening due to the magnetic fields. It is often a problem how to check ss 304 and 316 to confirm which material it is. Material check reports are the best way to check and confirm the material.

The are both similar when they are out of the factory. It is hard to visibly recognize them from each other. A clear inspection for rust can reveal the difference. The electrical resistance of 304 is higher than the 316 material. If you have some means of measuring that, you can differentiate them. For people who do not have much technical knowledge or resources, the easiest way is to have a rust test. The 304 material rusts in sea water and the 316 doesn’t. The sea water has sodium chloride. To replicate the effect, dipping the material in sodium chloride or kitchen salt solution. The 304 material will develop stain or rust while the 316 material won’t.

find out 304 vs 316 stainless steel machinability and magnetic properties


Chemical Material Composition Of 304 Stainless Steel
Typw Mn C P Si S N Mo Cr Ni
304 minimum 18.0 8.0
maximum 2.0 0.08 0.045 0.75 0.030 0.10 20.0 10.5



Yield Strength Of Grade 304
Grade Elongation (% in 50mm) minimum Strength of Yield 0.2% Proof (MPa) minimum Strength of Tensile (MPa) minimum   Pipes Hardness
Rockwell B (HR B) maximum Brinell (HB) maximum
304 40 205 515   92 201


Equivalent Material Of Stainless Steel 304
Type Old British Euronorm SS UNS JIS
En BS Name No
304 58E 304S31 X5CrNi18-10 1.4301 2332 S30400 SUS 304


Mechanical Properties Database Of Stainless Steel 316
Grade Elongation (% in 50mm) min Strength of Yield 0.2% Proof (MPa) minimum Strength of Tensile (MPa) minimum Pipe Hardness
Rockwell B (HR B) maximum Brinell (HB) maximum
316 40 205 515 95 217


Composition Standard Of SS 316
Grade Mn C Si P N S Cr Ni Mo
316 min. 16.0 10.0 2.0
max. 2.0 0.08 0.75 0.045 0.10 0.03 18.0 14.0 3.0


Equivalent Grades Table Of Stainless Steel 316
Type UNS Old British Euronorm JIS SS
En BS Name No
316 S31600 58E 304S11 X5CrNiMo17-12-2 1.4401 SUS 316 2347