List the three most commonly used methods of fastener surface treatment

Electroplating, hot-dip galvanizing, and mechanical plating on the surface of the fastener are the most common methods used. The process of forming a covering layer on the surface of the fastener. After the surface treatment of the fastener, it can show a more beautiful appearance. Appearance, the corrosion resistance of the fastener itself will also be improved. The more main purpose is to make the fastener itself obtain the anti-corrosion ability, so as to increase the reliability and adaptability of the fastener. Therefore, the quality judgment of the surface treatment of the fastener is mainly to check the anti-corrosion ability of the fastener. Whether the increase is effective, and whether the increase is in line with the expected requirements.

1. Electroplating of fasteners

The electroplating of fasteners refers to immersing the parts of the fasteners that need to be electroplated into a specific aqueous solution. The aqueous solution will contain some deposited metal compounds, so that after the current passes through the aqueous solution, the metal substances in the solution will precipitate And attached to the immersed part of the fastener. Electroplating of fasteners generally includes zinc, copper, nickel, chromium, copper-nickel alloys, etc.

2. Hot dip galvanizing of fasteners

Hot-dip galvanizing of fasteners is to immerse fasteners made of carbon steel into a bath of molten zinc with a heat of about 510℃, so that the iron-zinc alloy on the surface of the fasteners will be transformed into passivation Zinc to obtain a surface treatment effect. The price of hot-dip galvanizing of fasteners is higher than that of electroplating, about 1.5 to 2 yuan per kilogram.

3. Mechanical plating of fasteners

Mechanical plating of fasteners refers to the use of specific physical and chemical means to impact the surface of the fastener with the powder of the coated metal, so that the coated metal will form a coating on the surface of the fastener by cold welding , To achieve the surface treatment effect. The mechanical plating of fasteners is mainly applicable to spare parts such as screws, nuts and washers.