Tube fitting

A tube fitting comprising:

• a connection head having a thread portion adapted for thread connection to an object to be connected at one end, an annular collar projecting axially from a surface of another end of said connection head, and a first axial flow passage;
• a connection nipple having a connection portion adapted for plug-in connection to a pressurized fluid source at one end, an annular collar projecting axially from a surface of another end of said connection nipple toward said connection head, and a second axial flow passage;
• and
• an intermediate connection member having a third axial flow passage for communicating with said first and second axial flow passages, said intermediate connection member having a predetermined hardness and vibration absorption characteristics and being arranged between said connection head and said connection nipple to be held by said annular collars projecting axially from said end surfaces of said connection head and said connection nipple, and inserted into said intermediate connection member,
• wherein each of said annular collars projecting from each end surface of said connection head and connection nipple is provided with a protrusion around the circumferential surface thereof and said intermediate connection member is provided with channels corresponding to each of said protrusions for permitting said protrusions to press to fit in said channels so as to join said connection head, said connection nipple and said intermediate connection member.