Cut posts and rails to length with a hacksaw.
To make the basic frame of the headboard, position the two end posts vertically on the work surface and place the rails horizontally at the top and bottom to form a square.
Slide seven tension-rod brackets on each post. The two outermost brackets will attach to the rails at the top and bottom of the posts, the three inside brackets will hold the fencing in place, and the remaining two brackets on each side will be used to attach the headboard to the wall.
Attach a rail end cap to each of the four tension-rod brackets at the top and bottom of the posts, and fit the top and bottom rails into them. The top and bottom rails will be loose in the end caps until the fencing is stretched and attached to the posts.
With the basic frame in place, you can attach the fencing. Chainlink fencing is woven together and can be unwoven to create the 3 1/2"-wide piece needed for the headboard. Use pliers to unbend the top and bottom of one connecting piece of fencing, and slide it out of the fencing to unweave the connecting piece (Image 1).
Slide a tension bar in each side of the piece of fencing (Image 2).
Connect one side of the fencing to a post by bolting the tension bar to the three center tension-rod brackets on that post. To attach the other side of the fencing to the opposite post, pull the fencing tight, slip the tension rod into the bracket, and bolt in place (Image 1). This is a two-person job: one person pulls the fencing tight while the other bolts it in place.
Bolt the headboard to the wall with the remaining two brackets.
Add an end cap to the top of each post to finish the headboard (Image 2).