Surface treatment for steels：
• Satin Nickel：The Satin Nickel finish is nickel plating on metal or alloys and appearance of
   this plating layer will been dulled.

• Hard Chrome plating： Hard chrome plating is a technique of electroplating a thick layer of
   chromium onto a metal object. The chromed layer is used to reduce friction, add wear
   resistance and increase corrosion resistance. It is very hard, measuring between 66 to 70
   HRC.

• SQP：A Tufftride process includes preheating the steels first and then nitrocarburizing in
   acyanide–cyanate salt bath TF1 followed by post-oxidation in a nitrate–nitrite salt bath AB1.
   After the steels is cooling to room temperature, then polish the surface of the steels.

• Phosphate Conversion Coating：A type of conversion coating applied to passivate steels,
   aluminium, zinc, cadmium, copper, silver, magnesium, tin and their alloys to slow corrosion.

• Electroless nickel plating：An auto-catalytic chemical technique used to deposit a layer of
   nickel- phosphorus or nickel- boron alloy on a solid work piece, such as metals or plastic.

• Tin-nickel alloy plating：An alloy of tin and nickel (atomic ratio is 1:1) can be electroplated
   directly on copper, nickel and their alloys.

• Nickel-chrome plating：In order to further increase the corrosion resistance of the plated
   parts, under chrome coating the part would be plated with single or multilayer nickel. The
   multilayer nickel plating may have double-layer coatings or triple layer coatings.

• Zinc plating：Zinc (-0.7618V) is more electronegative than iron (-0.44). Steels are always
   plated zinc to prevent oxidation of the steel. If the plated zinc layer is damaged then the
   zinc would be as a sacrificial anode.