After firmly fastening the two sections together, return to the third hole which was left empty. In addition to a nut and bolt, you will also need a pipe ring bracket.

Install the 10mm nut/bolt again but with the bolt passing through the single holed side of the bracket. Hand thread and use 10mm wrenches to tighten.

Be sure the bracket is NOT installed between the edges of the dish sections.

The direction the bracket faces does not matter.