All my Stakes are 1/2 inch Rebar ...Just pound them in ....Weld a 1/4 inch bolt near the top ...Put sign on with loch washer and nut and then a wire tie at the bottom ...
We use fiberglass stakes. They will pound in with some frost, but it is hard on the top of the post. In the spots where the ground is to hard to pound, we pre drill the holes then pound the post in. But the posts are not much bigger then 3/4" around. We will just have a generator in the back of a truck with two drills with a 5/8" bit, one for each side. Thankfully we got 85% of our signs in before the big freeze up.