Stainless steel screw is made of metal, and metal anti corrosion mainly from four aspects, namely their material properties, the use of the environment, materials and environment interface and improved design of metal structure, if the complete resistance to corrosion of the alloy to produce stainless steel screws, unless there is a special need, otherwise in terms of economic idea is not practical, or screw appearance participating corrosion environment elements of a complete isolation, in practice are not necessarily line, can be very difficult. Metal structure design in a situation down to improve the effect of special circumstances, but most stainless steel screw design cannot fully revised and its role in the maintenance nor permanent were improved, and therefore this method basically can not deal with the problem, as long as in the interface of anti-corrosion, namely, the appearance is anti corrosion treatment is the most widely used approach.Stainless steel screw surface anti-corrosion treatment is refers to the use of various methods on the surface of the metal applied maintenance layer, its role is the metal and corrosion environment isolation to corrosion inhibition process, or to reduce the corrosive medium and metal surface contact, and reach the objective to avoid or mitigate corrosion of.The maintenance layer shall fit the following request:1, corrosion resistance, wear resistance, high hardness,2, the structure is tight, intact, the porosity is small.3, with the matrix metal separation and strong, good adhesion.4, the average distribution and a certain thickness.Maintenance layer are generally divided into two types of metal coated and non coated metal, metal coating is refers to with good corrosion resistance of the metal or alloy in easy corrosion of the metal surface protective layer and the coating is also called coating. Metal coating method and a lot of different varieties, of which the most common is plating method, followed by the molten metal plating (hot dip) and chemical surface treatment. Non metal coating is refers to the organic polymer materials such as paint, and inorganic materials such as ceramic, metal equipment or parts on the outside constitutes maintenance layer, the maintenance of the layer to the matrix metal and environmental media complete isolation, avoid the base metal due to the contact corrosion in stainless steel standard parts medium with the formation of corrosion.