Used a lot of angle iron back in the 70's and here is what I found: A bolt welded to the inside flat side of the angle pointing up to add a little height.......took a lot of abuse beating the stake into frozen ground, sometimes it bent after a few years use..... Used a flat washer under the bolt head, not welded, with a 1/4" hole drilled for an S hook connector (pre quick links)... worked OK but the bolt still took a beating........ I finally drilled a hole down approx. 1.5-2" on the angle and attached a short chain extension with a connector link (Everything was S-hook back then) so I could beat the top of the angle, then pull the loose chain fastened below the top of the angle and connect the trap above the top of the stake....... Believe it or not it wasn't bad and did not bind (minimum two universal swivels in the chain closer to the trap)........ You could use O'Gorman's idea of the Calvary Picket Pin that fell below the top of the bolt when driving it in if you want. I did that and used the side connectors from tire chains on some like Charlie Dobbins spoke of...... that worked OK but more "gear" than I wanted to use.......... hate a universal swivel of any kind at the stake as a little grass or mud and they are worthless for me in our soils. Went away from angle stakes in the 80's for re-rod where I could use them for both land and water..... I now use a similar system on my earth anchors and a 30 common nail through a washer but don't expect any swiveling action at the stake/anchor point..... Have tethered a lot of dogs (hounds, labs, pointers, terriers) in my day and every swivel at the stake gets bound sooner or later so I extend whatever (trap chain) connector point a few inches away from the earth point and let the farther up chain swivels do their thing.....................my take...................... the mike