I search for 316 stainless steel screw.
You're taking fate in your own hands with SS screws from china. I haven't had mixed results with Chinese stainless steel screws because they've all been bad. Even locally retailed Chinese screws (*cough* Bunnings *cough* Trademe *cough*) are junk. Cr@ppy 316 SS = 1/3 popped heads, and all with surface rust.
If I can't get what I want genuinely locally, American brand name supplies through Amazon are a much more reliable bet.
The builder on my brothers house was supposed to use stainless steel screws and they have all corroded. I am guessing they are cheap chinese ones too, as they were likely purchased from a big box hardware store. They still charge the earth for them. The prices in these hardware stores is so high, but probably due to lack of competition.