The most popular material used in pv mounting mid and end clamps are aluminum. While there are also stainless steel too.

To compare these 2 materials, they are both corrosion resistant. But aluminum panel clamps are usually lightweight while stainless steel clamps are heavier. From material performance speaking, the stainless steel do offer more support.

So if you have a upsupported roof, stainless steel pv clamps are what you can consider. But if you don’t, go with aluminum solar clamps.

The other thing to consider is corrosion. As we said both are corrosion resistant, but it doesn’t meant stainless steel won’t ever get rusty, it’s just under different situations the performance is better than some materials.

But as the solar panel frame being aluminum, if we use stainless steel mounting clamps, there will be a possibility that after raining and snowing while the moisture is added, hence the galvanic reaction between dissimilar metals. Aluminum and stainless steel can and do corrode when put together.

To sum up, if you are in a area with high wind speed and snow load, you may want to consider stainless steel clamps, if not, aluminum clamps will be your best choice.