Stainless steel is an alloy of iron, chromium, nickel, and other elements. Iron is the primary component, chromium provides corrosion resistance, and nickel enhances durability and strength. Elements like molybdenum, manganese, cobalt, and copper are also added to improve specific properties.
304 and 316 are the two most common grades, differing mainly in chemical composition—specifically the presence of molybdenum, which determines their corrosion resistance.
01 Chemical Composition
304 stainless steel contains 18% chromium and 8% nickel. It is the most versatile and widely used grade in the austenitic series. 316 stainless steel contains 16-18% chromium, 10-14% nickel, and 2-3% molybdenum. The addition of molybdenum makes 316 superior in corrosion resistance compared to 304.
02 Corrosion Resistance
While 304 has good resistance to oxidation in most environments, it is less effective against saltwater or chloride corrosion. 316 offers much stronger resistance to these elements, making it the preferred choice for chemical, medical, and marine equipment.
03 Strength and Hardness
Due to the molybdenum, 316 possesses higher strength and hardness than 304, allowing it to withstand higher temperatures and pressures. It is also more resistant to wear and fatigue, making it suitable for heavy-duty and high-load environments.
04 Price
316 is generally more expensive than 304 due to its complex composition and higher processing difficulty. Both are food-grade materials, but their applications differ: 316 is used for medical devices due to its high resistance, while 304 is widely used for cookware, cutlery, and kitchen countertops.
Maintenance Note: Stainless steel is not entirely rust-proof. In extreme conditions like high temperature, humidity, or salinity, it can still corrode. Proper maintenance and care are essential for long-term performance.
