Let me answer your question. There are practically no iron supports currently. Steel plate bracket PK aluminum alloy bracket. Products from regular manufacturers of the same thickness. Steel plate brackets are significantly better than aluminum alloy brackets. The advantage of aluminum alloy brackets is that they do not rust or corrode. Disadvantages: Insufficient strength and lightness.
In strong winds, it is easy to twist, deform or even collapse under load conditions. Steel brackets are usually cold rolled, hot galvanized, and then painted or sprayed. Even if the paint layer or plastic spray layer falls off, as long as the galvanized layer does not fall off, it will not rust, so the anti-corrosion performance is very good and there will be no problems for 10 years. Good strength and easy to repair.
The comparison does not pcouldn't have been blind. Under the same conditions, steel plate brackets are significantly better than aluminum alloy brackets.