The rod can be cut a little shorter than the maximum allowable length and threaded into the end caps. The end caps hold everything together like two nuts, exerting pressure and keeping everything together.
The threaded rod doesn't actually pass all the way through the end caps. It just looks that way. The effect is created with two 3/8 think discs placed into the face
The threaded rod doesn't actually pass all the way through the end caps. It just looks that way. The effect is created with two 3/8 think discs placed into the face