After watching the makerpipe video titled "Will it hold?", I thought I'd found the solution for mounting 3/4 emt to a flat surface that I'd been looking for. As one of the five solutions featured, it was demonstrated how an emt 3/4" compression fitting could be threaded into a 3/4" floor flange. Off to Lowes I went ...

Well, this unholy alliance of electrical and plumbing is not working for me. The compression fitting does not thread into the floor flange as shown in the video (where it threaded in very smooooothly). That stands to reason as the NPT thread in the floor flange is tapered while the EMT thread is not (at least that's my understanding).

Where have I gone awry?