304 SS.Nice work!
What grade stainless?
I made a similar grill grate for my Wolf gas grill.
I used 1” square solid stock for the frame. It was drilled to receive the rods. Only the end rods were welded to the bar.
I need to make a new one as I was stupid and did not use stainless rods.
Wait.... 1" SOLID??????? Holy cats, that'd be a heavy set of grates. 1" square 14ga tubing for mine.