Stainless Steel Sheet Metal Screws

I’m in the process of rebuilding my stainless steel BBQ gas grill, but I’ve always had a problem finding stainless steel sheet metal screws that don’t rust apart after a few years in this application. I’ve replaced the SS burner tubes and some of the reflector plates in the past, along with a number of mostly disintegrated SS sheet metal screws. I know that the high heat and other factors make this a rough environment for SS but all the other SS body panels and the larger SS nuts, bolts and washers have survived this environment for 20 years without rusting at all. In the past I’ve used SS sheet metal screws from the big box stores and local hardware stores, all with the same result. Does anyone know of a good source of high quality SS screws that will last as long as the rest of my grill?

It probably depends on the exact SS alloy. I would bet $0.50 that the larger fasteners are 316 and the sheet metal screws are only 303 or 304.

I used to work at a place that switched from using standard 303 stainless for raw component material to a “high machinability” 303. The HM303 products all came back months later covered in rust.

I’d probably look around on McMaster-Carr and see if the larger bolts have any markings to determine what alloy they are.

Sharx makes some marine grade sheet metal screws that are really good:
I think I ordered through Jamestown distributors, but it was years ago. There are provably other similar ones available if you search for marine grade sheet metal screws.

I’ve also had good luck with the ceramic coated Teks, but not sure if they make them small enough for what you need.