201 Stainless Steel (SUS), suitable for use in a dry environment, it is easy to rust with water. 304 Stainless Steel (A2), outdoor or humid environment, resistant to corrosion and acid.316 Stainless Steel (A4), added molybdenum, more corrosion resistance and pitting resistance, especially suitable for seawater and chemical media. This item is in the category "Industrial\Fasteners & Hardware\Screws & Bolts". The seller is "daniel8178" and is located in this country: CN. This item can be shipped worldwide.