The most intuitive is to distinguish by color:

Stainless steel is the primary color of iron. Galvanized screws are white, colored, black. Nickel-plated screws are silver.

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

2. The surface of galvanized screw is galvanized with white zinc, color zinc, black zinc, etc., so the color of galvanized screw is generally white, color, black;

3. The color of nickel-plated screws is related to nickel, generally showing a very bright silver.