I am making some bangles if there are any standard sizes.
Best thing to do is experiment/make different size pieces and try
them on different size people. I have used 2.50, 2.625 and 2.75-3.0
inches I'm still trying to decide on sizes for cuff type bracelets to
go on the arm above the elbow,, openings inside shape and dimensions.
I would like to spring hinge them also, but i haven't been able to
find them sold anywhere,, so sofar i must fabricate them, then i
could be ftc compliant also, for handmade...,,dp