How to distinguish between stainless steel screws, galvanized and nickel-plated screws?

Recently, many people have asked whether stainless steel, galvanized, and nickel-plated screws can be distinguished by the naked eye? Today, I will tell you how to distinguish from the following aspects:

　　1. Classified by color:

　　 a. Stainless steel screws are the primary color of iron and are made of stainless steel. The color of stainless steel is mainly an alloy of iron and carbon, so the color is close to that of iron.

　　b. The surface of galvanized screws is galvanized with white zinc, color zinc, black zinc, etc., so the color of galvanized screws is generally white, color, and black

　　c. The color of nickel-plated screws is related to nickel, and the color is generally very bright silver

　　 2. Distinguish with magnets: stainless steel is generally not magnetic, and the stainless steel screws that cannot be attracted by magnets. Galvanized and nickel-plated screws can be attracted by magnets.

3. Distinguish with oxidizer: metallic nickel has a strong passivation ability, and a very thin passivation layer can be quickly formed on the surface during electroplating, so there is a passivation film on the surface of the nickel-plated screw, and the galvanized surface is one Zinc layer, there is nothing on the surface of stainless steel, it can be distinguished by strong oxidizer.

4. Use strong acid and strong base to distinguish: stainless steel contains chromium and nickel, which has strong corrosion resistance and is not corroded by strong acids and alkalis. Nickel-plated screws have a passivation film on the surface, which is slowly corroded by strong acids and alkalis. Galvanized screws Corroded fast