Which stainless steel grade to use depends on the application. A web search will generate a good sample of the products available. 304, 316, 410 and 430 are stainless steel grades I have seen used in transportation applications when specifying threaded fasteners. 304 is a general use grade with a fair amount of nickle and chromium. 316 is a better grade we use near marine environments and has molybdium <sp?> in addition to the other metals. If you have strength requirements, as most applications will, you need to specify these as well because the chemical composition will not guarentee a specific strength. Somtimes cold working or other treatment will be used to produce a part with a specific strength.