I've worked with a lot of different stainless steels over the years and I've never heard of one with lead in it. Any of it might have some in, I suppose, in tiny amounts - so small it does not feature in the named metals SS is comprised of. And in such small quantities that even using the stainless for heavy duty catering would not be an issue. Someone may be repeating some sort of myth here if they say 304 grade SS (the most common) has any lead in it. Mind you, ultra-cheap SS in the 400 series might have just about anything in it as it's rubbish. So yes - if you have rubbish 400 stainless then it might be guilty of having contaminants in it. No reputable manufacturer of SS products would use 400, it might get used for screws that would need to be kept indoors, or similar.
For example 316 (marine grade/surgical grade) is commonly 18-12-2: chromium, nickel, molybdenum, the bulk is iron and perhaps small quantities of manganese etc. Proportions vary.
304 ('kitchen' or catering grade) is commonly 18-8: chromium, nickel, the bulk is iron etc. Proportions vary.
The highest grade you will easily locate is 312, which is about 30-10 Cr-Ni (the bulk is mostly Fe).
Lead is never mentioned in any of these common grades, neither is it in the 312 or 316 SS welding consumables (rods and wire).
Since most catering and kitchen SS is the 304 grade we might assume that lead isn't a problem even with this lower grade. Your sink drainer for example is 304, like your food bowls. It is perfectly safe to put food on/in, even cook with.
Lead might be found in some brasses, some cheap bronzes, and some free-machining grades of mild steel. No decent metals such as cupro-nickel, 316 SS, or good bronze such as nickel aluminum bronze contains lead, and neither does 304 SS (otherwise it wouldn't be used in catering). Mazac 'pot metal' used for cheap casting might have some in, this is the zinc-based metal that toy guns are made from.
If I found lead in any stainless I'd want my money back, it would be some kind of fault. The only functional difference between 304 and 316 is that 316 will survive harsh environments and corrosion better. However even that is theoretical because if you mirror polish 304 it will survive marine duty just as well as 316 that was not so well prepared. I'd vape through 304 if it is polished, there is no issue there. 316 is better but it's probably overkill.
