1. A TUBE-STRAIGHTENING TOOL COMPRISING A HOLLOW TUBULAR MEMBER HAVING AN INNER TUBULAR SURFACE, AND A PLURALITY OF ROUNDED PROJECTIONS ON SAID INNER SURFACE, DEFINED BY CORRESPONDING SPACED INDENTATIONS OF THE TUBULAR MEMBER AND EXTENDING INTERNALLY THEREOF, THE CRESTS OF THE SAID PROJECTIONS TOGETHER DEFINING A CHANNEL WHOSE TRANSVERSE WIDTH IS SUBSTANTIALLY EQUAL TO THE OUTER DIAMETER OF THE TUBE TO BE STRAIGHTENED.