First distinguish in color: stainless steel is the primary color of iron. Galvanized screw is white, color, black. Nickel-plated screws are silver.
Stainless steel screw is stainless steel material, the color of stainless steel is mainly iron and carbon alloy, so the color is close to the color of iron;
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, black;
The color of nickel-plated screws is related to nickel and generally presents a very bright silver.
Distinguish stainless steel screws, galvanized and nickel-plated screws other methods
Distinguish with magnets: stainless steel is not magnetic under normal circumstances, can not be adsorbed by the magnet is stainless steel screws, 410, galvanized and nickel-plated screws can be adsorbed by the magnet.
Distinguish with oxidants: metal nickel has a strong passivation ability, electroplating can quickly generate a thin layer of passivation on the surface, so the surface of nickel plated screw has a layer of passivation film, galvanized surface is a layer of zinc, stainless steel surface has nothing, can be distinguished with strong oxidants.
Distinguish with strong acid and alkali: stainless steel contains chromium and nickel, has strong anti-corrosion performance, not corroded by strong acid and alkali, nickel-plated screw surface has a layer of passivation film, corroded slowly by strong acid and alkali, galvanized screw is corroded quickly.
The elements of the metal were analyzed with a spectrometer.
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