Metal tubular connecting part and method for obtaining such a part by additive manufacturing

A metal tubular connecting part having at least an axis of revolution and a total axial length, said connecting part comprising:

• an inner surface and an outer surface, said inner surface and outer surface delimiting a wall,
• at least a first outer transition plane and at least a second outer transition plane, both of said outer transition planes being orthogonal to the axis of revolution,
• at least a first inner transition plane and at least a second inner transition plane, both of said inner transition planes being orthogonal to the axis of revolution,
• an outer transition surface which has a frustoconical shape defined by an outer transition generatrix having an inclination of angle al to the axis of revolution, said outer transition surface extending from the first outer transition plane as far as the second outer transition plane,
• an inner transition surface which has a frustoconical shape defined by an inner transition generatrix having an inclination of angle α2 to the axis of revolution, said inner transition surface extending from the first inner transition plane as far as the second inner transition plane, said outer transition surface and inner transition surface delimiting a transition thickness of the wall,
• a first male or female threaded end, having a first end plane orthogonal to the axis of revolution, a first inner diameter and a first outer diameter, said first end being defined by a first inner surface portion having an inner diameter and extending from the first end plane as far as the first inner transition plane, and by a first outer surface portion having an outer diameter and extending over a first axial length from the first end plane as far as the first outer transition plane, said first inner surface portion having a substantially cylindrical shape defined by a first inner surface generatrix, and said first outer surface portion having a substantially cylindrical shape defined by a first outer surface generatrix,
• a second male or female threaded end, having a second end plane orthogonal to the axis of revolution, a second inner diameter, and a second outer diameter, said second end being defined by a second inner surface portion having an inner diameter and extending over a second axial length from the second end plane as far as the second inner transition plane, and by a second outer surface portion having an outer diameter and extending from the second end plane as far as the second outer transition plane, said inner surface portion having a substantially cylindrical shape defined by a second inner surface generatrix, said second outer surface portion having a substantially cylindrical shape defined by a second outer surface generatrix,
• wherein a sum of the first and second axial lengths is less than or equal to the total axial length of the connecting part, and
• wherein the first end has a first thickness of the wall, the second end has a second thickness of the wall, and the transition thickness satisfies the following equation:
• [Math]1×max (E1;
• E2)≤W≤1.5×max (E1;
• E2)
• where:
• max (E1;
• E2) represents the largest value selected from the first thickness and the second thickness, and corresponds to the first thickness and to the second thickness when the first thickness and the second thickness are equal.