The description of the following Standard Cube Beamsplitter (see link below) says "Constructed by cementing two right angle prisms together"

I have two right-angled prisms that when placed together form a cube. There is no noticeable beam splitting that occurs.

How do I "join" the two right-angled prisms to get a 50/50 beam splitter?

Stanard Cube Beamsplitter: https://www.edmundoptics.com/f/Standard-Cube-Beamsplitters/12428/