Abstract: High pressure fiberglass tubing has been an important solution for corrosion of the conventional steel tubing. However, the well depth and application fields of fiberglass tubing had been largely limited due to its lower axial tensile properties caused by the weak thread connection. This paper studied the influence of thread component, thread profile, thread length and thread interface on connection properties of the high pressure fiberglass tubing (2 7/8 in, PN17 MPa) by using the impact test and tensile test. On the basis of thinking about the fabrication of thread, the tensile strength of thread can be highly improved by adding 1.1wt% short carbon fiber and 1wt% coupling agent (K550) with a suitable increased thread length. With the same fabrication process, the maximum failure load of the round thread is increased by 28% relative to that of the buttress thread. The connection property of the thread with the notched interface is not improved obviously. However, the notching process on the thread interface increases the complexity of the thread fabrication. Thus, notching on the thread interface is not recommended.

Key words: fiberglass, tubing, thread, connection