Step 5: Set the tension
To get the right tension on the pearl I started by forming the metal strip into a letter “U”. This was done with a pair of vise grips and the ¼” metal dowel of a grinding bit. From there I pinched the “U” shut over the dowel. See the pictures.
When I’d let go of the setting it would spring open just a little. To remedy this I held the setting closed and heated it until it was red hot. Next I quenched it in water. Now when I let go of the setting it stayed closed. This means the setting will want to spring closed instead of wanting to spring open.
The last two pictures are before and after heating.