Surface treatment of stainless steel screws and characteristics of self-tapping screws.
Under normal circumstances, the surface of stainless steel screws is usually smooth and does not require special surface treatment. However, some customers will put forward specific surface treatment requirements, which can not only meet their engineering needs, but also improve some of the performance and aesthetics of stainless steel screws.
So how much do you know about the surface treatment of stainless steel screws?
1. Electroplating: the part is immersed in an aqueous solution containing metal compounds and metal is deposited on the surface of the part by electric current. Common electroplating includes zinc plating, copper plating, nickel plating, chromium plating, copper-nickel alloy plating and so on.
two。. Hot-dip galvanizing: carbon steel parts are immersed in a molten zinc solution at a temperature of about 510 ℃ to form a passivation layer on the surface of iron-zinc alloy to zinc. A similar process is hot-dip aluminizing.
3. Mechanical plating: by spraying metal particles, a coating is formed on the product surface, and the coating is fixed on the product surface by cold welding. Electroplating is usually used for screws, but hot-dip galvanizing is usually used for hexagonal wood screws used outdoors. 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 higher.
Among those who are interested in screws, many people may know something about tapping screws. It may also be different. Screw manufacturers are constantly innovating ideas to produce higher quality products and 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.
Let's talk about thread forming self-tapping screws. This kind of screw comes from the development of sheet metal. In use, we need to drill holes in advance, and then screw into the hole to form the match of internal and external threads. This is how thread forming tapping screws work.