Morning Neal,
I used half by two inch bar stock with the one edge sharped like a stone chisel for gripping. I'm probably going to replace it with one built the same way and dimensions but the piece on a plane with the front--rear of the tractor being three inch. I've bent it a couple of times on heavier posts.
It's one of those things that are just handy as a pocket on pants. /forums/images/graemlins/grin.gif