How To Connect Two 4mm Cords

Hello, I am making some necklaces or lanyard ID holders. I am using poly cord and want to string some beads and charms on the cord as well as the ID holder.


I can't seem to find the piece that will crimp and hold the two ends of the cord tougher without using a clasp of some sort.

The ones you buy have a long tube like piece that appears to be crimped on. The only ones I have seen are very tiny, this cording is about 4 mm diameter. Do you have any suggestions?

Thanks,

Chris