Threaded pipe joint

A threaded joint for pipes defining an axis (21), comprising a coaxial male member (1) consisting of a pipe provided with a threading on a portion of its outer surface in proximity of at least one of its ends (13) and a female coaxial member (2), consisting of a pipe or sleeve provided with threading on a portion of its inner surface in proximity of at least one of its ends (14), wherein the male member (1) is provided with a cylindrical portion, intermediate between its ends having walls of a constant thickness and wherein the male member is provided at said at least one of its ends (14) with an annular abutment surface (9) and wherein a corresponding annular abutment surface (10) is formed on the inside of the female member (2), said threadings being adapted to screw on reciprocally and reversibly to produce a contact between said annular abutment surfaces (9, 10), said threadings being complementary and wherein the thread profile, in a section along a plane containing the axis (21), defines a load flank (4, 3) forming a first angle (α) with respect to a plane perpendicular to the axis (21) and defines a lead-in flank (6, 5) forming a second angle (β) with respect to a plane perpendicular to the axis (21), characterized in that said second angle (β) has a value between 10 and 25°, and in that when the joint is assembled and the contact between said annular abutment surfaces (9, 10) is achieved, in absence of axial loads, there is provided, between the lead-in flank (6) of the threading formed on the male member and that (5) of the thread made on the female member, a gap of a size between 0.01 and 0.12 mm, measured along a direction parallel to the axis (21) of the joint, and in that the internal diameter (D3) and external diameter (D4) of the cylindrical length of said male member (1), the internal diameter (D1) and external diameter (D2) of the abutment surface of the female member being linked in the relationship (D22−D12)/(D42−D32)≧0.5.