Connecting stove pipe to boxwood stove
If the stove is from Germany or another country the flue pipe may be sized in centimeters and not inches as here in the U.S.A. By the way, the flue pipe fits over the cast iron collar and not inside the collar to insure that the flue gasses do not flow to the outside of the pipe. Flue gasses always flow from a male fitting to a female fitting so that no flue gasses escape and to reduce turbulence.