The process of passing a rotating tool through a tubular workpiece such as a heat pipe having longitudinal capillary grooves in the walls thereof such that a swaging ball carried by the tool flattens the lands between the grooves to thereby produce a capillary configuration in which the width of the...http://www.google.co.uk/patents/US4004441?utm_source=gb-gplus-sharePatent US4004441 - Process for modifying capillary grooves
