1/2 x 1 in wire for rats?

I have quite of bit of spare 1/2 in by 1 in wire (mesh). I'm having someone build me a rat rack and thought about using it for that. I will be using jumbo litter pans. My question: Is 1/2 in by 1 in wire too large for rats?

People use the 1/2" hardware cloth, which is 1/2" x 1/2". I don't really see that the hole being bigger in one direction would make a difference. Unless I'm missing something when I'm trying to visualize it. BUT, if they are able to bend the wire, then you'd end up with holes that are more like 3/4". That would be a problem. Even then I think it would be ok for adults.