We are often asked if stainless steel door hardware is fine for external situations. The answer is yes, as long as you keep it clean! By the sea or in any caustic environment expect everything to melt in minutes but if you keep it clean as per the manufacturer's instructions it will last longer. This grade 316 stainless steel letterplate has been outside our showroom, inland and in clean-ish air but under cover from direct rain for a year. We have not cleaned it and is showing signs of tarnishing already. Lower grades would be ruined. Imagine what it would look like if it was in direct rain or by the sea! Look after your stainless steel door furniture and it will look after you!