Stainless steel screws generally use SUS201, SUS304, or SUS316 materials, with the most common material being SUS304. After the production of stainless steel screws is completed, many of them are directly cleaned, then packaged and shipped. So does it need to be pickled and passivated by an electroplating plant? Today, I will talk about the importance of the common SUS304 material screws:
Although the stainless steel screw material itself has strong rust resistance, it still requires passivation treatment. Due to the characteristics of the material, stainless steel screws can be used without electroplating, but they can also rust if the environment is particularly harsh. In order to improve the rust prevention performance of stainless steel screws, we can conduct a pickling and passivation treatment to improve its rust prevention effect.
During the production process of stainless steel bolts, such as the heading process, the surface of the screws may be stained with iron filings and oil stains generated during the processing process. If these are not removed, they can affect the aesthetics of the screws and even lead to rust. Generally, surface treatment through acid pickling and passivation is required to remove impurities from these surfaces.
The so-called pickling and passivation treatment is that electroplating plants use acid and passivation solution to soak stainless steel screws to form a passivation oxide film on their surface. After passivation, the oxidation resistance of stainless steel screws is greatly improved, and the salt spray time can easily reach 48 hours or even 240 hours.