I'm not an expert, but I use 308L filler on 304L Stainless. 309L on stainless to carbon and 316L on 316L stainless. And Im not sure but I think food grade is 304L.

I believe any of the 300 series stainless steels are good as "food grade" materials. The actual choice at the end of the day will be based on the corrosive properties of the food being processed.

In applications where contamination must be minimized, there are other considerations, such as the elimination of small crevices and other surface irregularities. As such, these components are usually polished following the fabrication process.

If you are welding 304L, then certainly I would recommend the use of 308L filler.

Hope this helps

Regards
Niekie Jooste

The majority of your "Food Grade" SS is 304L and 316L. 304 is a General Purpose alloy and 316 has improved corrosion resistence from 304. Pay attention to the surface condition. 2b finish is usually used to start with and electro polished to reduce the roughness even more. The use of polishing and reduced Ra in food processing is to eliminate the possibilty of bacteria staying on the surface and growing. Thus the reason for the EP.