Oops, I meant bangling. My wife has me making bangles for my daughters, nieces, sister, sister in law and of course her. I took advantage of a day off and finished these off. These are all metal core. I think that I will try a segmented one and a bentwood one next.
The metal core is 2 rings that snap together. The basic process is to start with a round blank, turn out the center so that metal rings will slip in from both sides, turn the blank to the proper width, snap in and glue the core, shape and finish the outer edge. You can purchase blanks or make them from wood scraps.
They come in several sizes and the web site has some guidance on sizing. My wife has a slip on bracelet that I measured and used as a guide for sizing. I have one neice with large hands and I am worried about fitting her.
A large canning lid can be used as a guide as well.