Disclosed within is a slit section pass formation unit having a pair of rolls and a de-ribbing means, where the pair of rolls has a roll profile configured to produce a pair of slit rods with symmetrical dimensions, the pair of slit rods connected via a rib, and the de-ribbing means to remove the rib in its entirety forming a first slit rod and a second slit rod.

A superconducting wire comprises a MgB.sub.2 filament, a base material, a high-thermal expansion metal, and a stabilizing material. The high-thermal expansion metal is a metal (for example, stainless steel) having a higher thermal expansion coefficient at room temperature than the MgB.sub.2 and the base material (for example, iron or niobium). The manufacturing method includes a step of packing a mixed powder in a first metal pipe, a step of performing wire-drawing on the first metal pipe formed of the metal to be the base material, a step of producing a composite wire by accommodating the first metal pipe in a second metal pipe formed of the high-thermal expansion metal and the stabilizing material, a step of performing wire-drawing on the composite wire, and a step of performing heat treatment.

A process for producing an ornamental chain includes arranging a cylindrical polymer core inside a tubular metal casing to form a layered tubular profile, cutting and bending the layered tubular profile to form a plurality of shaped chain links, and connecting the shaped chain links to form an ornamental chain. In some embodiments, the forming of the layered tubular profile can include extruding the cylindrical polymer core and inserting the cylindrical polymer core into a hollow section of the tubular metal casing.

Disclosed is an extruded aluminum wire including: Fe, Cu, Ti, Mn, Mg, Cr, B, Ga, V and Zn in the total content of 0.01% by mass or less, and one or more components selected from the group consisting of Ni, Y and Si, with the balance being Al and inevitable impurities, wherein, in a cross-section perpendicular to the longitudinal direction of the extruded wire, an average grain size measured by electron backscatter diffraction is 15 to 50 m, respectively, in both a central measurement region including a center point of the cross-section and a peripheral measurement region in contact with the outer periphery of the cross-section.

A steel wire is composed of a steel containing not less than 1.0 mass % and not more than 1.1 mass % C, not less than 0.15 mass % and not more than 0.25 mass % Si, not less than 0.25 mass % and not more than 0.35 mass % Mn, and not less than 0.15 mass % and not more than 0.25 mass % Cr, with the balance being Fe and unavoidable impurities. The steel wire has a wire diameter of not less than 0.15 mm and not more than 0.42 mm. The steel has a pearlite structure. The steel has a dislocation density of not less than 2.410.sup.16 m.sup.2 and not more than 5.010.sup.16 m.sup.2. The steel has a full width at half maximum in a circumferential direction of not less than 42 at a peak of a maximum intensity of a Debye ring for Fe (211) plane.