Abstract
A micro screw and a micro nut are developed by utilizing extra fine wires which materials are molybdenum and tungsten, and their diameter are 20 micrometers. The micro screw and micro nut have a pitch of 40 micrometers, and their major diameters are 0.54 millimeters. The micro-screw made as follows; a pair of a molybdenum wire and a tungsten wire is coiled around a needle pin, and the coiled wires are soldered with lead-free solder on the needle pin. The tungsten wire is removed from the soldered needle pin, the molybdenum wire remains around the needle pin as the screw thread. The micro-nut is made as follows; the coiled pin with the molybdenum wire and the tungsten wire is inserted into head hole of a split pin, and the coiled wires are soldered with lead-free solder on the inside of the head hole. The needle pin and the tungsten wire are removed from the head hole, the molybdenum wire remains inside of the head hole as the screw thread of the nut. In this paper, making process of the micro-screw and the micro-nut were described, and the product screw and nut were estimated by experiments.
