People often confuse anodes with the base metal they are made of. A zinc anode does not just contain zinc, but a range of other carefully quantified elements. The same applies to the aluminium and magnesium versions. This ensures each anode is effective at protecting underwater structures from corrosion.

What Is A Top Quality Anode Made From?

Some dubious manufacturers recycle the anodes (nothing wrong with that), but the residual alloy can contain impurities that hugely affect how the anode will work. When buying anodes you should always look for the Quality Assurance and Certification of the manufacturer. It means their production is regularly checked for consistency, accuracy and effectiveness of the anodes. Good quality anodes don’t have to cost the earth, but check the credentials of the manufacturer before purchase.

At Anode Outlet we ONLY sell anodes from reputable manufacturers who can demonstrate they have the required certification and quality assurance in place. You can rest assured that the prices are great and the quality is too.

For more information on cathodic protection, please read here.

Specification Of Aluminium Anodes For Use In Salt and Brackish Water:

Specification Code AL-CHEM 1

Composition (weight %)

Iron Fe 0.12 max.
Silicon Si 0.05 – 0.15
Copper Cu 0.003 max.
Zinc* Zn 3.0 – 6.0
Indium In 0.015 – 0.030 max.
Mercury Hg 0.001 max.
Titanium Ti 0.025 max.
Others each 0.02 max. (<0.1 total)
Aluminium* Al Remainder
Capacity- Amp.hr/kg Typically 2760

Specification Of Magnesium Anodes For Use In Fresh Water:

Specification Code Magnesium Alloy High Purity

Composition (weight%)

Copper Cu 0.08
Aluminium Al 5.3 – 6.7
Silicon Si 0.3 max
Iron Fe 0.005 max
Manganese Mn 0.25 min
Nickel Ni 0.003 max
Zinc Zn 2.5 – 3.5
Lead Pb 0.03
Magnesium Mg Remainder
Potential Ag/AgCl -1.5 V
Capacity- Amp.hr/kg 1230

Specification Of Zinc Anodes For Use In Salt Water:

Specification Code US MIL Spec 18001K

Composition (weight %)

Iron Fe 0.005max.
Cadmium Cd 0.025-0.07
Copper Cu 0.005max.
Aluminium Al 0.10-0.50
Lead Pb 0.006max
Others total 0.10max
Zinc Zn Remainder
Potential Ag/AgCl -1.05 V
Capacity- Amp.hr/kg 780