I used round ones, simply because thats what I had from my old van. I do not think it matters. One other thing for what its worth. originaly they had plastic rods, which because you need to remove the plastic feet in the steps and you need a small clearence so the weight rests on that rod. I changed them for 5mm bolts to take the weight. It also ment that I could place two nuts either side of the step leg to stop it from wandering.
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