I once soldered one of the brass things to a music rod. I had to clean the rod with steel wool, and use flux to get it to stick. I heated the brass thing and put the solder down into it while it was still in the heat. Then I dunked the very clean music rod into the flux and placed it in the heat too. When all seemed hot I slid the rod into the brass thing. Once completely cool I pulled like heck with vicegrips on both and it held very well. I probably could get it to break if I really wanted too, but no servo I own would be able to. I've done this with the brass things on steel cable too. It worked just as well.