Even go so far as to impress and confuse the guy at West Marine by asking/demanding 316L stainless steel. Grades 303, 304, 308 are all typical consumer grades of stainless, they all still contain iron. Not alot but enough to start the oxidization, rusting, process. Once it begins it will spread like cancer and eat away at the clamp. 316L is a medical grade, implantable, stainless that all of the iron has been blown out during the casting. By leaving in a small amount of iron it makes the metal easier to machine. Stainless kitchen knives are generally 304ss as it is easier to sharpen. It does not hold it's edge as long as it could but the ease of the end user to sharpen is a larger benefit. How many of your stainless knives and utensils come out of the sink with rust spots after a while? Quite a few of them. That expensive ss chef knife you bought that sat in the bottom of the sink for a few days seems to get little rust spots all over, those are where the iron bits remained.