410S is generally considered to be weldable by the common fusion and resistance techniques. Special consideration should be given to avoid brittle weld fractures during fabrication by minimizing discontinuities, maintaining low weld heat input and occasionally warming the part somewhat before forming. 410S is generally considered to have slightly poorer weldability than the most common
ferritic stainless steel grade 409 stainless steel. A major difference can be attributed to the alloy addition to control hardening which results in the need for higher heat input to achieve penetration during arc welding. When a weld filler is required, AWS E/ER 309L or 430 filler material is most often specified.
