High quality carbon steel. It has good workmanship and high strength up to a temperature of about 800 degrees. They have rust resistance and excellent oxidation resistance in poor environments such as high temperatures, cold weather and high humidity, which can guarantee a long time. li> Different screw sizes: M2.4.M2.20, M3.4.M3.30, M4.6.M4.30 to meet different requirements. It is a very important manual tool for the family. With M2, M3 and M4 nuts and washers, installations are now more precise and the contact area increases, reducing pressure and protecting parts and screws The nuts and washers are arranged in a storage box, which allows you to easily find in series and avoid losses if necessary. li> They are also antioxidant and corrosive at high temperatures. The main application of stainless steel hexagonal screws is very widely used in electronics, electrical appliances, chemicals, water, machinery and equipment, furniture and many other fields. Dimensions: Material: