Most types of stainless steel can be welded, but the degree of efficiency depends on the grade. Here are some tips for welding each category of stainless steel:

Austenitic: most grades of the austenitic family, except for free-machining Grade 303, are well-suited for welding purposes. However, this group is susceptible to sensitization and inter-granular corrosion on thicker products. For projects that involve welding thick materials, it may be better to use low carbon content grades such as 304L or 316L. Some stabilized grades, such as Grade 347, may also be effective.

Martensitic: these grades are also good options for welding, but may be prone to cracking. To help reduce the likelihood of fractures, pre-heat and post-heat the material, or use supplementary austenitic filler rods.

Ferritic stainless steel: though relatively less suitable for welding, some stabilized ferritic grades, such as Grade 409, may be appropriate for certain projects. Issues such as sensitization, low ductility, and high grain growth may be overcome with the help of austenitic stainless steel fillers or by post-heating the welded material.

Duplex: this set of grades works well for low thermal expansion and is welding efficient. Some suitable welding grades such as Grade 2205, have higher nickel content to improve ductility, strength, and corrosion resistance.