The thin-walled stainless steel is inserted into the socket of the compression type pipe fitting, and the stainless steel pipe is clamped in the pipe junction with the clamping tool. The cross-section shape of the clamping position is hexagonal. In addition, there is an O-ring between the stainless steel pipe and the pipe junction, which makes it have the characteristics of anti leakage, anti pulling, anti vibration and high pressure resistance.