How to distinguish stainless steel screws, galvanized and nickel-plated screws
1, stainless steel screw is the primary color of iron, is stainless steel material, stainless steel color is mainly iron and carbon alloy, so the color is close to the color of iron;
2, galvanized screws surface galvanized white zinc, color zinc, black zinc, etc., so the color of galvanized screws is generally white, color, black;
3，The color of nickel-plated screws is related to nickel, generally showing a very bright silver.
Stainless steel is generally not magnetic, can not be absorbed by magnets is stainless steel screws, galvanized and nickel-plated screws can be absorbed by magnets.
Distinguish with oxidizer: metal nickel has a strong passivation ability, electroplating can quickly generate a thin layer of passivation on the surface, so the surface of nickelized screws has a layer of passivation film, galvanized surface is a layer of zinc, stainless steel surface is nothing, can be distinguished by strong oxidizer.
Distinguish by strong acid and alkali: stainless steel contains chromium and nickel, has strong corrosion resistance, is not corroded by strong acid and alkali, nickel-plated screw surface has a layer of passivation film, by strong acid and alkali erosion is slower, galvanized screw corrosion speed is the fastest of the three.