Can definately be done. If the spring tension is too strong it can be adjusted.
It would be advisable to use U shaped clamps to connect this caster to a chain link fence.
I did the same.
You need a door spring to hold more weight
Using 2 of these gate casters, will support a load of 250 pounds total. So long as your gate does not exceed that weight limit, these casters will be a great solution!
Not sure how the wheel fits next to the hinge post when you swing it out. It might work if you give a little wiggle room for the wheel.
It would be recommended to place this gate caster on the back side of the gate to swing inward. The entire depth of the plate is is 4-1/8 inches (or 3-1/2 inches from the edge of the plate to the center of the spring.) Apologies that we do not have a picture or diagram of the caster attached to a metal gate, we are in the process of gathering lifestyle images for all of our products.
About 2 1/4” center to center and I’d guess 3/8”. I have 1/4” lag bolts holding mine in place.
Im sure some grease on/in them would be good but in over a year I have not and see no way to do it.
I don't know about Required per se, but it makes sense to me to use the largest that will fit your constraints. If you mean what is the smallest you can safely get away with, I suppose that answer would depend heavily on gate's weight, the level of use, the material being attached to, and the rolling surface.