How to distinguish between stainless steel bolts, galvanized and nickel plated bolts for electric heating pipes

How to distinguish between stainless steel bolts, galvanized and nickel plated bolts for electric heating pipes

Firstly, it is determined by color - stainless steel is the metallic color of iron, galvanized screws are white, colored, or black, and nickel plated screws are silver.

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

2. The surface of galvanized screws is coated with white zinc, colored zinc, black zinc, etc., so the color of galvanized screws is usually white, colored, or black;

3. The color of nickel plated screws is related to nickel, usually reflecting a very bright silver color.

Alternative methods for distinguishing stainless steel screws, galvanized and nickel plated screws

1. Use a magnet to distinguish

Stainless steel usually does not have magnetism, and what cannot be attracted by magnets is stainless steel screws. Galvanized and nickel plated screws can be attracted by magnets;

2. Use oxidation reaction to distinguish

Metal nickel has strong passivation ability. During the electroplating process, it can quickly transform into a thin layer of passivation on the surface. Therefore, there is a passivation film on the surface of nickel plated screws, and a layer of zinc on the galvanized surface. There is nothing on the stainless steel surface, which can be distinguished by a strong oxidant;

3. Distinguish with strong acids and bases

Stainless steel contains chromium and nickel, which has strong corrosion resistance and is not corroded by strong acids or alkalis. There is a passivation film on the surface of nickel plated screws, which corrodes slowly by strong acids or alkalis, while galvanized screws corrode quickly.

summary

The method of distinguishing stainless steel screws, galvanized and nickel plated screws from their appearance is to look at the color of the screws. The color of stainless steel screws is close to the metallic color of iron, while galvanized screws are white, colored, and black, and nickel plated screws are very bright silver. In addition, magnets, oxidation reactions, and strong acids and alkalis can also be used to distinguish stainless steel screws, galvanized and nickel plated screws.