There are a variety of surface treatment methods for inch bolts, the following are several common methods:
electroplate：
Galvanizing: Depositing a layer of zinc on the surface of the bolt through electrolysis has good corrosion resistance. The galvanized layer can be blue and white, colorful or black.
Chromium plating: The chromium plating layer has high hardness, good wear resistance and beautiful appearance, but the cost is high.
Nickel plating: Nickel plating layer has high hardness, good wear resistance and corrosion resistance, suitable for high corrosion environment.
Hot dip plating:
Hot dip galvanizing: the bolt is immersed in molten zinc to form a layer of zinc-iron alloy on the surface, which has strong corrosion resistance and is suitable for outdoor and harsh environments.
Electroless plating:
Electroless nickel plating: Using chemical reaction to deposit a layer of nickel on the surface of the bolt, the coating is uniform and dense, and has good corrosion resistance and wear resistance.
Dacromet treatment:
The zinc-chromium coating technology has excellent corrosion resistance, heat resistance and permeability after treatment, without the risk of hydrogen embrittance, and is commonly used in the automotive and aerospace fields.
Coated with anti-rust paint:
Primer: Coated with an epoxy zinc-rich primer that contains a large amount of zinc powder to provide cathodic protection and enhance rust prevention.
Top paint: Then coated with acrylic polyurethane top paint, with good weather resistance and decorative, can effectively prevent external corrosive media from eroding bolts.
Mechanical plating:
The surface of the product is impacted by particles of coated metal and the coating is cold-welded to the surface of the product.
Black (blue) :
Through chemical treatment, a blue-black protective film is formed on the bolt surface to improve corrosion resistance.
Phosphating:
A phosphating film is formed on the surface of the bolt, which has worse corrosion resistance than galvanized, but the cost is lower.
These surface treatments can be selected according to the specific use environment and requirements to ensure the quality and reliability of the bolt.