Can I use the balls from a metal bar on PTFE?
It depends. Metal jewellery normally allows you to remove only one ball from the bar. You may find that some barbells will unscrew both ends. One end should undo easily, but you may need force on the other end - careful, you don't want to damage the ball. Some manufactures NOT US weld the ball at the fixed end. So if you want to use the balls from your existing jewellery, it may take 2 metal barbells to make 1 PTFE barbell. Titanium and Steel BANANABELLS are designed so that only the top ball is removable! Don't even think about removing the bottom ball ... you might damage the ball, or even destroy the jewel! Why not make the difference and start with a PTFE barbell or bananabell. You can change both ends with ease.