Originally Posted by
Skipjacks
Reduces the chance of the screw rusting onto the frame too. That's less of an issue if you use a steel screw on an aluminum frame. That's more of an issue when both the screw and the frame are the same material (both aluminum or both steel)
Actually it more of an issue if the are different metals because of galvanic corrosion. With an exception, stainless steel. Use stainless and grease.