An end surface structure having a pipe member, a first lid and a second lid is disclosed. The pipe member has two opposing open ends. The first and second lids each has an interlocking member to frictionally fit the first and second lids with the pipe member at the open ends. Each of the first and second lids further has a flange extending outwardly and radially from the interlocking member. The thickness of the flanges is larger than the interior periphery of the open ends but no larger than the exterior periphery of the heat pipe. When the first and second lids are fitted with the heat pipe at the open ends, a welding process is performed to permanently connect the heat pipe with the first and second lids.