Those metal clips are D-rings, you would find these on the back of frames and they are found in hardware stores near all the other picture hanging hardware. I used Gorilla Glue (see update below) and glued the D ring to the plate for about $.10 a plate. Keep in mind, this is somewhat permanent. In theory you can scrap/chisel gorilla glue off but I wouldn’t do this to any plate you would ever want to use in another way. They have been up for months and have 3 boys thundering by them daily and are still hanging firmly where I put them.
I laid my plates on the floor to get a layout, and did a few rough measurements to decide how high to hang the top one. Mostly I eyeballed it and tried to space them evenly. I love the results! Dirt cheap too!
Need a plate collection? I can find them for you, CHEAP! Message me for details!
UPDATE: I have since used an ES 6000 type glue and I like it even better for this purpose, but it stinks so use in a well ventilated area.
Find me on pinterest, instagram as selinagj, or my facebook page. In all of these places you’ll find lots of repurposed projects!