To provide the production method to produce an inner face grooved heat transfer tube having narrow, high fins in a low cost and high reliability.
The method consists of a fin forming process to form a fin and groove on one face at least of the bar stock T by passing between a pair of fin forming rolls 14, 16 while running the bar stock T of copper or copper alloy annealed after cold rolling, a tube forming process to form the bar stock T formed with the fin and groove to a tubular with passing plural forming rolls 20 and a welding process to weld both end edges of the bar stock T formed to a tubular with heating and butting. Further, before the fin forming process, a surface roughness of both faces S1, S2 of the bar stock T is made to 0.05-0.30μm Ra.
NAGAHARA KOTARO
MIYAUCHI ATSUSHI
KONO HARUO
