Unscrew broken tap (or cast iron pipe) from thread
Recently I wanted to install a garden tap (also looked like this) made of cast metal.
According to the well-known rule "to firmly come off" broke the "noble" part in half, and stupidly so that I could not grasp the already screwed-in fragment with the pipe wrench.
The solution of the problem
Wood screws. Simply insert as many as possible into the opening and then clamp with a screwdriver, with 2-3 other screws.
This construct can then be grasped with the pipe wrench and turned out. The screws have not even been damaged here.