Surface treatment steps for stainless steel self-tapping screws

Normally, the surface of stainless steel screws is usually smooth and does not require special surface treatment, but some customers will put forward specific surface treatment requirements, which can not only meet the customer’s engineering needs, but also improve some performance and aesthetics of stainless steel screws.

How much do you know about the surface treatment of stainless steel screws?

1. Electroplating: Immerse the parts in an aqueous solution containing metal compounds, and pass the current to deposit the metal on the surface of the parts. Common electroplating includes zinc plating, copper plating, nickel plating, chrome plating, copper-nickel alloy plating, etc.
2. Hot-dip galvanizing: Immerse carbon steel parts in a molten zinc solution at a temperature of about 510°C to form a passivation layer on the surface of the iron-zinc alloy. A similar process is hot-dip aluminum.
3. Mechanical plating: By spraying metal particles, a coating is formed on the surface of the product, and the coating is fixed to the surface of the product by cold welding. Screws are usually electroplated, but hexagonal wood screws used outdoors are usually hot-dip galvanized. The cost of electroplating is generally 0.6-0.8 yuan per kilogram, and the cost of hot-dip galvanizing is generally 1.5-2 yuan per kilogram, which is relatively high. Among friends who are interested in screws, many people may have some understanding of self-tapping screws, which may be different. Screw manufacturers are also constantly innovating ideas to produce higher quality products to make our lives more diversified. Therefore, many screw manufacturers will systematically summarize the screw market. Self-tapping screws can actually be divided into several types, including thread forming, thread cutting, thread rolling and self-drilling, etc. Let’s talk about thread forming self-tapping screws first. This type of screw is developed from sheet metal. When using it, it needs to be pre-drilled and then screwed into the hole to form the combination of internal and external threads. This is the working principle of thread forming self-tapping screws.