We bought two twin headboards.  They are beautiful.  However, we spent a good amount of time getting them to work.  The bolts used to secure the headboards to the frames are 5/16 inch.  These bolts must be used as they thread into receptors in the headboard.  The slats and holes in most bed frames are 1/4 inch (see link below).  There are some that have larger holes but typically they are for larger (queen/king beds).

We considered an adapter, however, because we were not adjusting left to right there was no way to secure the adapter and still be able to insert into the headboard frame.  As a result our only option was to purchase two new bed frames.  The ones we had to buy adjust to fit bed sized from twin to king.

Finally we found the bolts provided are also too long.  They protrude at least 1/2 inch beyond the wood bed frame slats.  This could lead to scratching the wall.  We plan on trying to cover them with something.