I found myself making a small nut for a screw to hold a decorative silver piece on a leather band. In order to hold it while I made the threads, I left one side long. Then when I was finished I cut it down to size.
I needed to solder the screw post onto the back of my silver piece. But the piece wouldn't stay level on a flat surface. So, I carved out a charcoal block to hold the uneven surface of the piece while keeping the back level.Then I used locking tweezers to hold the post tightly against the back while soldering.