405 stainless steel is a type of ferritic stainless steel that contains 11.5-14.5% chromium and is often used in applications where mild corrosion resistance and good weldability are required. It also contains small amounts of nickel and molybdenum, which provide additional corrosion resistance and strength.

One of the key advantages of 405 stainless steel is its ability to be easily welded, even without preheating or post-weld heat treatment. This makes it a popular choice for fabrication and manufacturing processes that require welding, such as exhaust systems, heat exchangers, and automotive components.

405 stainless steel is also known for its good resistance to oxidation and scaling at high temperatures, making it suitable for use in high-temperature applications such as furnace parts and heat treatment equipment.

However, it is important to note that 405 stainless steel may not be suitable for applications where high levels of corrosion resistance are required, as it has lower corrosion resistance than other types of stainless steel such as 304 and 316.