I'm trying to replace a gas stove in a house from 30+ years ago.
We have the stove, and now are struggling with trying to connect it.
I tried to replace the old flex hose with a new stainless steel hose,
but the connector diameters are off by 1/16" - even with adapters.

The sizes of the connectors are confusing to me,
because the "name" is different vs the actual measured diameter.
ie - the 1/2" naming is actually measured as 3/4" diameter ???

Here is what I am seeing and measuring as far as real diameters.....

The existing shutoff value with a male thread -
that used to be connected to old flex hose
OD -- 13/16" (3/4" + 1/16")

The old flex hose - female connectors both ends
ID -- 13/16" (3/4" + 1/16")

New stainless steel flex hose
ID -- 7/8" (14/16")
New screw-in male to male adapters
OD -- 3/4" (12/16") --[]-- 7/8" (14/16")

Suggestions on how to resolve this short term ?
Why or where did my 13/16" for the pipe and old stove come from ??

I will be calling (plumber ??, heat/cooling ??, appliance ??)
Who's best qual to mess with the black pipe connector ?
to rework the end of the black pipe and install a new shutoff
with the current threading to match the avail adapters.

tnx - Phil -

The connectors like have on your old flex line were outlawed about 30
years ago. The flare nut on that size of line had threads that were
similar to 3/4 pipe threads and people put the flex lines directly onto
pipe w/o the proper flare adapter causing major leaks, fires and
explosions. I think there was also a smaller size line that would screw
onto 1/2 pipe. They had to change the sizes so there is no way to do
that. You will have to get a new lline with the proper shutoff and flare
adapter for the stove. As to who should do the work, I guess it would
depend on your local codes and regulations. You will have to call
around. Maybe call the gas co. first and see what they recommend. Sorry
I can't help you any more than that. It shouldn't be that major of a job
for someone to come out and take care of it for you. Larry

BTW - why does a 3/4" actual diameter connector get called a 1/2" connector
??

Phil Schuman writes:

BTW - why does a 3/4" actual diameter connector get called a 1/2"
connector

It goes by the ID of the standard gage straight pipe, not the OD of the
pipe or major diameter of the threads.