What does “L” mean in stainless steel?

The L indicates the low content of carbon in the stainless steel, L grades stainless steel can reduce the possibility of carbide precipitation in welding and other processes. Carbide precipitation may lead to intergranular corrosion, in which the material becomes more sensitive to possible corrosion. Generally, carbon is maintained at 0.03% or less; however, it may vary depending on the referenced code or standard.