dpb writes:
On 05/08/2016 6:56 PM, dpb wrote:
Salvaged some old EMT for reuse with some tool-free connectors that turn
out to be quite neat to use--they're similar in appearance to a pipe
fitting solder connector with just a couple of dimples pressed into the
barrel on each end. In use, you simply drive the conduit in and it's
there; not compression nuts to tighten nor the ugly external screws in
the screw-type.

...

... I can't make out a manufacturer mark more
than an uppercase 'M' and a patent-pending to try to identify...

Followup on the "who" ...

I came across some additional pieces-parts in the salvage--anybody able
to identify a manufacturer from the initials MT?

Could it be "metallic tubing"?


I did do some more searching and haven't found anything currently on the
market similar to the couplings but they're surely handy and think
they'd be cheap to produce as compared to either of the present
alternatives. Wonder why they didn't catch on...

Probably not reliable enough due to a friction fit.

Or perhaps the unions thought they were too easy for joe homeowner to use.