I Have a CD Rack With a Strange Metric Thread

I have a clever CD rack made of female threaded tubing. Two lengths of tubing are joined by a short length of all-thread whose ends have grooves for a slotted screwdriver. A foot is placed on each leg using a similar arrangement. I'd like to convert it into two shorter racks and make a new set of feet, better suited to our baseboard. The all-thread clearly matches a 1.5 mm pitch, so the thread is metric. When I measure the OD of the threads it measures 0.424 inches or 10.78 mm, which makes no sense to me.
Would a designer go to the bother of creating a product that requires non-standard threaded parts?
thanks,
baumgrenze

Threads are never manufactured perfect, and size variations are allowed within the thread standard.

Most likely that is a M11 x 1.5 6g class thread.

See:

[url]https://www.engineersedge.com/hardware/metric-external-thread-sizes1.htm[/url]