摘要 |
A heat pipe is provided with a multiplicity of longitudinal deep grooves and ridges formed in the inner peripheral surface thereof. A plurality of shallow grooves are formed by a plastic work in the top surfaces of the longitudinal ridges separating the deep grooves. Parts of burrs formed as a result of the plastic work for forming the shallow grooves are extended over the deep groove so as to form bridges connecting adjacent ridges over the deep grooves. |