What is the difference between 304 and 316 stainless steel

304 and 316 stainless steel are the two most widely used stainless steel casting grades in the world. Both have excellent corrosion resistance and use value.

1. Differences in chemical composition

304 stainless steel contains 16% to 24% chromium, as well as small amounts of carbon and manganese. The most common form is 18-8 stainless steel. It contains 18% chromium and 8% nickel. The 316 grade has almost the same physical and mechanical properties as 304 stainless steel. The main difference is that 316 stainless steel contains about 2% to 3% molybdenum. The addition improves corrosion resistance, especially against chlorides and other industrial solvents.

2. Performance Differences

304 stainless steel is the most common type of steel. As a widely used metal, it has good corrosion resistance, heat resistance, low temperature strength and mechanical properties. It has good hot workability such as stamping and bending. There is no heat treatment hardening phenomenon (non-magnetic, operating temperature -196℃～800℃).

316 stainless steel has excellent corrosion resistance, atmospheric corrosion resistance and high temperature strength due to the addition of molybdenum. It can be used under harsh conditions. Excellent work hardening (non-magnetic).

3. Application Differences

304 stainless steel application range

Kitchen accessories such as sinks and splashbacks, pans, cutlery, utensils, cabinets.

Kitchen appliances such as refrigerators and dishwashers.

Household items such as indoor plumbing, water heaters, boilers, bathtubs.

Heat exchangers.

Commercial food processing equipment, breweries, pharmaceutical production equipment.

Manufacturing nuts, bolts, screws and nuts.

Water pipes, storage tanks, indoor electrical housings, automotive interiors.

Decorative strips.

316 stainless steel application range

Chemical piping.

Pharmaceutical equipment.

Medical equipment and tools.

Stainless steel floats.

Structural steel and components in marine environments.

Manufacturing of food, chemical and petroleum production and processing equipment.

Laboratory bench and equipment construction.

Building paneling in coastal areas.

Marine hardware and pipes.

4. Heat treatment differences

The annealing process of 304 stainless steel heat treatment is carried out in the temperature range of 1850 to 2050 degrees. Then rapid annealing and rapid cooling are carried out. 316 stainless steel cannot be hardened by heat treatment.

5. Welding Differences

Between 304 and 316 stainless steel, 316 stainless steel has good welding performance. All standard welding methods can be used for welding.

When welding, 316Cb, 316L or 309Cb stainless steel electrodes or rods can be used for welding according to the application.

For the best corrosion resistance, 316 stainless steel welded parts need to be annealed after welding. If 316L stainless steel is used, no post-weld annealing is required.