To attain improvement of execution efficiency by facilitating centering operation and setting operation of root opening.
A connecting tool 1 is disclosed comprising a top holder 11 that can be attached to and detached from the lower periphery of an upper first vertical piping 3A, a bottom holder 12 that can be attached to and detached from the upper periphery of an lower second vertical piping 3B, a guide plate 13 that is installed in the top holder 11 and that guides the second vertical piping 3B coaxially relative to the first vertical piping 3A, and a screw shaft 14 that connects the top holder 11 and the bottom holder 12. The screw shaft 14 is configured to be installed in a manner that one end 14a in the screw shaft direction can rotate on the top holder 11 around a direction orthogonally crossing the axial direction of the first vertical piping 3A, in a manner that the other end 14b is held on the bottom holder 12 so that the screw shaft direction and the axial line direction of the second vertical piping coincide with each other, and in a manner that the bottom holder 12 is made to move along the screw shaft direction.
Tadashi Takahashi
Takashi Watanabe
Yoshifumi Saeki