It's actually 1" stainless steel tubing, about 1/16" thick that was a high-end curtain rod. Pretty strong. I use a piece about 16" long for the footpegs on my T-bar row machine and I've not bent that piece yet. They're 5" long and sink 2-1/2" into the 4x4, so they also won't twist out or blow out the wood. You can just barely push one into the 1" hole barehanded.