Durable for long term use : High quality 304 stainless steel provides strength and good corrosion resistance in many environments. With M3, M4, M5 and M6 nuts and washers, installations are now more precise with an increased contact area, which reduces pressure and protects parts and screws. Material: Made of 304 stainless steel, with superior rust resistance and good heat resistance to ensure long lasting results Superior Quality: Made from high quality stainless steel. The sturdy screw set represents good corrosion resistance in harsh environments such as high temperature, cold weather and high humidity areas. They are perfectly resistant to rust and oxidation, which allows a long service life and prolongs the service life. The thread is very precise and clean. It can make your job easier. Our screws and nuts comply with the standardized metric system