My first thought was: how the heck could you assemble a metal cube? Putting a plastic one together relies on the springiness of the material in order to place the final piece, but metal won't give in the same way. The solution:

> The face centers each receive a hollow stem that screws into the 5/16-24 thread. This assembly holds a captive spring-loaded screw, which screws into the core. The spring provides some give to the entire unit and allows the cube to be assembled and disassembled easily by snapping pieces in.

Brilliant!