In stainless steel applications, 304 and 304L are often confused. Both belong to the austenitic stainless steel category and share a high degree of visual similarity. However, due to core compositional differences, their properties and suitable scenarios are entirely distinct. Industry insiders emphasize that accurately distinguishing their characteristics is crucial for ensuring production safety and effective usage.

Carbon content represents the most fundamental difference between the two. 304 stainless steel has a maximum carbon content of 0.08%, while the “L” in 304L stands for low carbon, strictly limiting carbon content to under 0.03%. This subtle difference directly determines their core properties: 304, with its higher carbon content, offers slightly superior tensile strength (≥515MPa) and yield strength (≥205MPa) compared to 304L, along with lower costs and a significant cost-performance advantage. 304L, leveraging its low-carbon nature, virtually eliminates the risk of intergranular corrosion caused by chromium carbide formation during welding or thermal processing, offering superior weldability.