Grade 430(16/0) and 304 (18/10) are two common types of stainless steel that are used in various applications, including plumbing and kitchen appliances. Although both are stainless steel, they have some important differences in terms of composition, properties, and applications. Because grade 304 contains between 8 – 10.5% nickel, it is much more expensive, in some cases double the price of grade 430.
Grade 430 (16/0) stainless steel is a ferritic type of stainless steel that contains around 17-20% chromium and less than 0.12% carbon. It is magnetic and has good corrosion resistance in a dry to slightly humid environment, such as residential kitchens. However, it is not as corrosion or rust-resistant as grade 304(18/10) stainless steel and is typically not used with harsh chemicals, or extreme hygiene environments such as in hospitals or high-temperature environments.
Grade 304 (18/10) stainless steel is an austenitic type of stainless steel that contains around 18% chromium and 8% nickel (the expensive part). It has excellent corrosion or rust resistance and is commonly used in commercial sinks, plumbing fixtures, and other applications where exposure to water and corrosive substances is a concern. It is non-magnetic and it’s easier to bend and weld. Although it has good rust and corrosion resistance, grade 304 is not immune to staining, rust or corrosion. Long exposure to stagnant high chlorides in borehole water of both metals will cause discoloration and deterioration of the metal. In these cases the stainless steel needs to be cleaned and water flushed regularly. Build-up of salts on the surface of the steel due to condensation will also cause staining, corrosion and rust. Proper care and maintenance will prevent any damage.
So the main differences between grade 430 and 304 (18/10) stainless steel are their composition, corrosion or rust resistance, and suitability for different industrial and commercial environments, especially hospitals and food processing plants. Grade 304 stainless steel is generally considered to be of higher quality and more versatile. Grade 304 is less prone to metal fatigue in commercial and industrial use. This is sometimes a serious problem with grade 430 where the joins crack with heavy use.