Metal anchor expansion tool are manufactured from steel which can corrode or rust in a moist environment. Because of this, manufacturers paint or coat the metal parts of the tool to help extend its usable life.
The most common types of corrosion protection used on the metal parts of metal anchor expansion tools are powder coating, black oxide and electro plating.
What is powder coating?
Powder coating is a type of finish usually found on metals that, instead of a conventional liquid paint, uses dry powder cured under heat. A much tougher finish can be achieved with powder coating than conventional painting methods.
Although many colours can be achieved with powder coating, metal anchor expansion tools are nearly always black. This helps to reduce glare from reflected light which could result in eye strain. Glare could be a problem if you are using an inspection lamp to illuminate a confined area you are working in.
ADVANTAGES
DISADVANTAGES
Produces less glare than electro plating finish
Many colours can be achieved
Less expensive than other coatings
Does not provide the same level of corrosion protection as black oxide or electro plating
What is black oxide?
Black oxide has many trade names. Unlike other coatings such as powder coating, which only bonds to the surface and does not chemically react, black oxide is a coating formed due to a chemical reaction with the iron in the metal to produce a protective surface of magnetite (Fe3O4).
This chemical bonding makes black oxide a superior quality corrosion protection compared with others used on metal anchor expansion tools.
ADVANTAGES
DISADVANTAGES
Matt finish creates less glare than other corrosion protection
Provides better corrosion protection than powder coating
Black is the only colour that can be achieved
What is electro plating?
Electro plating coats the steel in a layer of zinc or nickel for corrosion prevention. The part that is being plated is dipped in a solution called an electrolyte that contains metal ions.
An anode made of the metal which the part is to be coated with is connected to a positive electrical terminal and also placed in the electrolyte, while the part is connected to a negative terminal to form what’s known as the cathode. A DC (direct current) is applied through the anode and cathode. This causes the metal of the anode to dissolve ions into the electrolyte, which are then deposited on the cathode.
Some metal anchor expansion tools have some of their parts electro plated while others are coated with black oxide.
ADVANTAGES
DISADVANTAGES
Provides a better corrosion protection than powder coating
Creates more glare than other corrosion protection finishes