On Sep 16, 10:24*pm, Tom wrote:
We have hot water radiant heat in our house. *After having our bathroom re-tiled, the radiator now sits 3/8" higher than previously so the two pipes coming out of the floor are 3/8" too short. *I cannot remove the 3/4" steel pipes, because I do not have access to the other ends. *A male/female coupling extends the pipe too much (about an inch) and I do not want to put the radiator up on blocks. *I also do not want to cut the legs of the radiator to shorten it. *Is it possible to cut the threads off of the supply and return pipes and place a brass (or steel) fitting on the end that is a compression fitting for a 1" OD pipe and has a 3/4" NPT fitting on the other end?

Use a masonry drill of the proper size to remove an
appropriate amount of the tile from beneath where
the "legs" of the radiator sit to lower the height of
the radiator and match the pipes...

As others have mentioned this should have been a
foreseeable issue during the remodel... The floor
apparently is 3/8" higher now than it used to be,
what about the transition to the room/hallway
outside the bathroom, or is that covered by
a large threshold ?