My charm beads are fully cored with a piece of sterling silver tube, flared around the bead hole itself. There is no glue and it cannot fall out. I painstakingly cut, smooth and flare each tube into place before putting it through several stages of hand polishing and rigorous quality control.

Hole size: 4.8mm
This fits on most brands of charm bead bracelets Tr0ll, P@ndora etc.