18/8 and 304 actually refer to the same type of stainless steel, just expressed in different ways. The "18" in 18/8 indicates that this type of stainless steel contains 18% chromium, and the "8" refers to its nickel content of 8%. The corresponding number for this chemical composition in the American Iron and Steel Institute (AISI) standard is 304.

Difference: 416 is a free-machining martensitic stainless steel with higher sulfur content, offering improved machinability over 304.
Recommendation: Select 416 for applications requiring extensive machining and moderate corrosion resistance.

Difference: 420 stainless steel is a high-carbon martensitic stainless steel, offering higher hardness and strength, but slightly lower corrosion resistance compared to 304 stainless steel.
Recommendation: If you need a material with excellent corrosion resistance at higher temperatures, 304 stainless steel is likely the top choice. If you require cutting tools or blades, 420 stainless steel may be the better option, as it has higher hardness and strength characteristics at lower temperatures compared to 304 stainless steel.

Difference: 304L has a lower carbon content than 304, which provides better weldability and reduced risk of carbide precipitation.
Recommendation: 304L stainless steel has slightly better corrosion resistance and weldability compared to 304, making it more suitable for welded applications in corrosive environments, while 304 is more commonly used in general-purpose applications.

Compared with 340, 316 contains molybdenum, so it has a stronger corrosion resistance if your stainless steel needs to be used in marine or industrial chemical environments that require superior corrosion resistance,316 is a good choice.

304 stainless steel has better corrosion resistance and mechanical properties, making it suitable for more demanding applications, while 430 stainless steel is a more economical choice for less corrosive environments.  Use 430 for decorative applications and kitchen appliances where high weldability is not required.

316L stainless steel has superior corrosion resistance, especially in chloride-containing environments, such as marine and chemical environments, due to its higher nickel and molybdenum content, making it the preferred choice for applications that require enhanced corrosion protection. 304 stainless steel is a more economical option for applications with less demanding corrosion requirements.

316L stainless steel has superior corrosion resistance, especially in chloride-containing environments, such as marine and chemical environments, due to its higher nickel and molybdenum content, making it the preferred choice for applications that require enhanced corrosion protection. 304 stainless steel is a more economical option for applications with less demanding corrosion requirements.

304 stainless steel has better corrosion resistance due to its higher nickel and chromium content, but it is also more expensive, while 201 stainless steel has lower corrosion resistance but a lower price, making it suitable for applications that do not require high corrosion resistance, such as decorative pipes and industrial pipes.

Difference: 441 is a ferritic stainless steel stabilized with niobium, offering good oxidation and corrosion resistance similar to 304 but with better high-temperature strength.
Recommendation: Opt for 441 in automotive exhaust systems and applications requiring good corrosion resistance at elevated temperatures.