PURPOSE: To provide an anticorrosion mechanical joint by which corrosion of the end face of a steel pipe to generate red water and leakage of fluid in the pipe can be prevented when lining steel pipes are connected to each other.

CONSTITUTION: The end part of a lining steel pipe 1 of which the inner circumferential face is coated with resin, is provided with a first enlarged diameter receiving port 11 having a little larger bore than the outer diameter of a connected lining steel pipe 1, and a second enlarged diameter receiving port 12 which is further enlarged on the extreme end side of the former port. The end part of the connected lining steel pipe 1 is inserted into the first receiving port 11, a rubber ring 3 is provided between the outer circumferential face of to pipe end and the second receiving port 12, a presser nut 2 is threadedly engaged with the thread 13 provided on the outer circumferential face of the second receiving port 12, and the rubber ring 3 is pressed with the nut 2. Further, the inner circumferential face of the end part of the connected lining steel pipe 1 is closely contacted with the outer circumferential face of cylindrical body 6 mounted on the inner side of the first receiving port 11 and connected to it. Hereby, leakage of fluid in the pipe and generation of red water can be surely prevented.