Abstract: An electrically conductive wire includes a core wire made of metal, and a coating layer made of stainless steel covering a surface of the core wire. The metal constituting the core wire has an electrical conductivity greater than that of the stainless steel. The core wire includes a diffusion layer containing not less than 0.5 mass % Fe, arranged to constitute the surface of the core wire. The diffusion layer has a thickness that is not less than 0.4% and not more than 5% of the diameter of the core wire.

Abstract: An oil tempered wire includes a steel wire and a lubricant coating disposed around an outer circumference of the steel wire, wherein the lubricant coating includes a lubricant component resin and a binder resin, the lubricant component resin is at least one selected from polyacetals, polyimides, melamine resins, acrylic resins and fluororesins, the deposited mass of the lubricant coating is not less than 1.0 g/m2 and not more than 4.0 g/m2, and the surface roughness Rz of the steel wire is not more than 8.0 ?m.

Abstract: An oil tempered wire includes a steel wire and a lubricant coating disposed around an outer circumference of the steel wire, wherein the lubricant coating includes a lubricant component resin and a binder resin, the lubricant component resin is at least one selected from polyacetals, polyimides, melamine resins, acrylic resins and fluororesins, the deposited mass of the lubricant coating is not less than 1.0 g/m2 and not more than 4.0 g/m2, and the surface roughness Rz of the steel wire is not more than 8.0 ?m.

Abstract: An oil-tempered wire that has high fatigue strength and toughness after the nitriding treatment, and a method of producing the same, and a spring using the oil-tempered wire are provided. The oil-tempered wire has a tempered martensite structure. A lattice constant of a nitride layer formed on a surface of the wire is 2.870 ? to 2.890 ? when the oil-tempered wire is nitrided. The oil-tempered wire is produced by wire drawing a steel wire and quenching and tempering the wire drawn steel wire. The quenching is performed after the radiation heating is performed at 850 to 950° C. for over 30 sec to 150 sec, and the tempering is performed at 400 to 600° C.

Abstract: The present invention provides a spring steel wire which has a tempered martensitic structure brought about by quenching-tempering. The present spring steel wire has a 40% or higher reduction of area and a 1,000 MPa or higher shear yield stress after subjected to heat treatment for at least hours at a temperature ranging from 420° C. to 480° C. The present steel wire preferably constitutes, based on mass %, C: 0.50-0.75%, Si: 1.80-2.70%, Mn: 0.1-0.7%, Cr: 0.70-1.50%, Co: 0.02-1.00%, and remnants consisting of Fe and impurities, or constitutes, based on mass %, C: 0.50-0.75%, Si: 1.80-2.70%, Mn: over 0.7-1.50%, Cr: 0.70-1.50%, and remnants consisting of Fe and impurities.

Abstract: An apparatus for measuring gas leakage including a hollow container having a gas inlet port which is connected to a reference pressure gas supply via a valve and another gas outlet port that is connected to a test container; a liquid container located in the hollow container, a balance mechanism mounted within the hollow container which is maintained in equilibrium by an inverted floating cup that is attached to the underside of the balance beam and which is immersed in a liquid contained in the liquid container, a supply pipe that introduces gas at a reference pressure into the floating cup, a detector which detects the inclination of the balance mechanism and generates a signal corresponding thereto, a measuring device that measures the displacement of the floating cup as a function of the signal from the detector, and a restoring means that will restore the equilibrium of the tilted balance beam.