Method of manufacturing thick-walled small diameter pipe

A method for machining at least one thick-walled small diameter pipe that has been manufactured by extension and heating processes, said pipe having a longitudinal axis and an inner circumferential surface approximately concentric with the longitudinal axis, said method for machining said pipe being operative to uniformly cut away portions of the inner circumferential surface of said pipe despite any eccentricity of the inner circumferential surface relative to the longitudinal axis for removing defects and achieving smoothness in said pipe, said method comprising the steps of:

• providing a core bar having opposed first and second ends, a cutting tool being disposed on said first end thereof, portions of the core bar spaced from the cutting tool on the first end being dimensioned to fit into the pipe;
• holding the core bar in proximity to the first end thereof;
• inserting the second end of the core bar into and through the pipe;
• holding the second end of the core bar;
• releasing the first end of the core bar;
• rotating the pipe about the longitudinal axis;
• generating relative longitudinal movement between the pipe and the core bar such that the cutting tool of the core bar follows the inner circumferential surface through the pipe and uniformly cuts away the inner circumferential surface of the pipe.