How To Distinguish Stainless Steel Screws, Galvanized And Nickel-plated Screws?

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

Firstly, distinguish by color:

Stainless steel is the original color of iron. Galvanized screws come in white, colored and black. Nickel-plated screws are silver in color.

 

Stainless steel screws are made of stainless steel material. The color of stainless steel mainly consists of an iron and carbon alloy, so its color is close to that of iron.

 

The surface of galvanized screws is galvanized with white zinc, colored zinc, black zinc, etc. Therefore, the colors of galvanized screws are generally white, colored and black.

 

The color of nickel-plated screws is related to nickel and it typically shows a very shiny silver hue.

 

Other methods to distinguish stainless steel screws, galvanized screws and nickel-plated screws:

1. Use magnets to differentiate: Under normal circumstances, 3 series stainless steel is non-magnetic and cannot be absorbed by magnets. Screws that cannot be absorbed by magnets are stainless steel screws. (4 series of stainless steel such as 410 is magnetic), and 410, galvanized and nickel-plated screws can be absorbed by magnets.

 

2. Distinguish by oxidizing agent: Metal nickel has a strong passivation ability. Electroplating can quickly form a thin layer of passivation on the surface. Thus, the surface of nickel-plated screws has a passivation film. The galvanized surface is a layer of zinc and the stainless steel surface has nothing. This can be distinguished by a strong oxidizing agent.

 

3. Distinguish by strong acid and alkali: Stainless steel containing chromium and nickel has strong anti-corrosion performance and is not corroded by strong acid and alkali. The surface of nickel-plated screws has a passivation film and is eroded slower by strong acid and alkali. Galvanized screws are corroded the fastest.

 

4. Analyze the elements of the metal with a spectrometer.