Durable for outdoor use Long Term: High quality 304 stainless steel provides durability and good Resistance to corrosion in many environments. With M3, M4, M5 and M6 nuts and washers, installation is easy Contact surface that reduces pressure and protects parts and screws. Material: handmade; Made of 304 stainless steel, with resistance greater than rust and good corrosion resistance. heat for long-lasting results quality; Upper: Made from high quality stainless steel. The robust screw set stands for good resistance to damage. Corrosion in harsh environments such as hotspots; high temperatures, in cold and very humid weather. They are totally resistant to rust & oxidation which ensures durability and prolongs life. The thread is very precise and clean . It can make your work easier. Our screws and nuts correspond to the standardized metric system