PURPOSE: To fix a steel tube to a chain simply, safely, and exactly by a method in which a chain-fixing base plate and a covering plate are rotatably connected to clamps to hold steel tubes, and the link of a chain is detachably connected to the chain-fixing base plate and the covering plate.

CONSTITUTION: Nuts 10 are loosened to develop a bolt 9 around a pin 12, a covering plate 7 is removed from a notch 7b and opened, and one of oblong links 1a making up a chain 1 is fitted on a projection 6a. The covering plate 7 is again closed, a bolt 9 is coupled with the notch 7b of the plate 7, and a recession 7a is coupled with the projection 6a and clamped with the nuts 10. A nut 4f is then fastened, a surrounding pieces 4 is opened, a steel tube 11 is inserted into the central space, and the surrounding piece 4a is closed. The nut 4f is clamped and the tube 22 is strongly held by the surrounding pieces 4a and 4b to fix it. The steel tube 11 can thus be fixed to the chain 1 simply, safely, and exactly.