To provide a clamp wherein a gripped pipe can be slid in the axial or peripheral direction.

The pipe is passed through a grip portion 4 of the clamp 1, and then a screw 20 is inserted from a seat face hole 15 through an upper insertion portion 5 and a lower insertion portion 6 and a nut is threaded thereto at the back side of a plate member to be mounted. When the screw 20 is fastened, the upper insertion portion 5 and the lower insertion portion 6 are moved closer to each other and the diameter of the grip portion 4 is shrunk to fasten the pipe. When the screw is further fastened, a base portion 12 is crushed due to unbearable load. As, the fastening force operates around an insertion hole 7, and a part of the crushed upper insertion portion 5 is pushed out to the side of the grip portion 4 and the fastening force of the grip portion 4 on the pipe is relaxed. Thereby, the pipe gripped by the grip portion 4 can be slid in the axial or peripheral direction.