Tie a knot on one end of your joiner, add one 5/8″ hex nut, both 5/16″ nuts, then the remaining 5/8″ nut. Done.
If you decided to include the washers and spacers, add the washers in between the two hex nuts on each side. Add the spacers so that they fit inside of the 5/16″ (the smaller) washers. I’ll explain the purpose of these below.
If you decided to include the super glue, roughly sand each side of the washer, and the sides of the hex nuts that would touch it. Glue the washer to the 3/8″ (larger) nut. You can optionally glue the smaller nut to the larger nut also. I also usually glue the nylon spacer to the inside of the 5/16″ nut. The spacer can also be glued to the washer somewhat.
You can swap the 5/16″ beads for nylon equivalents for lighter beads. These hex nuts are usually found individually-packaged at the hardware store. The nylon spacers are usually packaged in pairs or individually.
The purpose of the spacers and washers are to help keep the cord somewhat centered in the beads. You can easily make usable begleri without them, but they’re also cheap additions that are easy to add.
If you chose to glue your beads, they’ll most likely come apart at some point due to impacts or drops from use. You can re-glue or scrape off the dried glue and reglue. If you do use glue, I’d give it a day to dry or overnight to be safe. If you use the beads too early, glue can get on the cord and make it a pain to get it out of the bead when you go to change joiners.
In closing, you can use any size hex nuts you like, and any number of them to get the weight and feel you want. I personally like the feel of the smaller nut on top with the larger weight at the bottom. Equally good setups are just using 4-6 5/16″ beads together, or 3 smaller hex nuts on each end. It’s a really inexpensive and easy way to create your own set to play around with.
See below to see an example of the materials for my favorite build from my Instagram.