A method for producing a hollow part (17; 21; 46) made of a metal material, includes preparing a blank (1; 18; 33) of the metal material of the hollow part (17; 21; 46), and at least one sacrificial mandrel (2; 19; 34, 35) made of a material which has a yield stress in the range from −30% to +20% of the yield stress of the material of the blank (1; 18; 33), preferably in the range from −15% to +10%, ideally in the range from −5% to +3%; applying a punch (10) on at least one of the ends of the blank (1; 18; 33) in order to produce the expansion of at least a portion of said blank (1; 18; 33) and to create at least one internal space (12; 20; 36, 37) inside said blank (1; 18; 33); inserting a sacrificial mandrel (2; 19; 34; 35) in said an internal space (12; 20; 37) of the blank (1; 18; 33);crimping the sacrificial mandrel (2; 19; 34, 35) in said blank (1; 18; 33);producing, by co-forging, a simultaneous deformation of said blank (1; 18; 33) and of said sacrificial mandrel (2; 19; 34, 35), with a homothetic ratio K; and performing a machining in order to remove the sacrificial mandrel (2; 19; 34, 35).

A method for producing a brazing wire consists of unwinding a solid metal or metal alloy wire, of circular or substantially circular cross-section and subjecting the wire to a stamping operation between rotating rollers, the periphery of which respectively having a die for receiving the full wire and a punch capable of deforming the wire and of generating a U-shaped cross-section across substantially the entire original diameter of the wire. The method also consists of filling the volume defined by the U using brazing flux or pickling flux in a powder or paste form and closing the arms of the U, after filling of the volume with the flux, one on top of the other with the end of one of the arms of the U overlapping the other. The method also consists of calibrating and shaping the resulting wire, according to the desired diameter and cross-section.

The present disclosure relates to a method for producing a rod-shaped element. In order to provide a method with which it is possible to produce a rod-shaped element which overcomes at least one of the disadvantages of the rod-shaped elements known from the state of the art, it is proposed according to the invention that the method has the steps of providing a tube made of a metal, wherein the tube has a longitudinal direction, providing at least one strand with a plurality of threads, wherein at least one of the threads has carbon fibres, introducing the at least one strand into the tube, with the result that the at least one strand extends in the longitudinal direction in the tube, and cold forming the tube, together with the at least one strand, using a forming tool, with the result that an outside diameter of the tube before the cold forming is larger than the outside diameter of the tube after the cold forming.

Disclosed are a micro fiber and a method of manufacturing the micro fiber are proposed. The micro fiber may be manufactured by controlling thickness and Young's modulus thereof using hollow fiber.

A tungsten wire according to an embodiment is a tungsten wire made of a W alloy containing rhenium, and includes a mixture on at least a part of a surface thereof, the mixture contains W, C, and O as constituent elements, and taking a radial cross-sectional thickness of the mixture as A mm and a diameter of the tungsten wire as B mm, an average value of a ratio A/B of A to B is 0.3% to 0.8%.

Embodiments of the present invention provide a hollow cylindrical filter for removing efficiently foreign substances from fluids. This is performed by forming complicated passages including an axial direction and a radial direction in the filter. The hollow cylindrical filter is formed by winding a metal wire rod in a spiral and multilayered manner. The metal wire rod includes a recess formed throughout the entire length in a longitudinal direction, or recesses repeated along said longitudinal direction. Some wire rod layers extend in an axial direction of the hollow cylindrical filter while the adjacent wire rod layers extend in an intersecting direction, thereby forming a plurality of communication paths for communicating between the overlapping wire rod layers. Additionally, a space is formed between the recess of one wire rod layer and another adjacent wire rod layer, allowing the plurality of communication paths to communicate with each other.

Embodiments of the present invention provide a hollow cylindrical filter for removing efficiently foreign substances from fluids. This is performed by forming complicated passages including an axial direction and a radial direction in the filter. The hollow cylindrical filter is formed by winding a metal wire rod in a spiral and multilayered manner. The metal wire rod includes a recess formed throughout the entire length in a longitudinal direction, or recesses repeated along said longitudinal direction. Some wire rod layers extend in an axial direction of the hollow cylindrical filter while the adjacent wire rod layers extend in an intersecting direction, thereby forming a plurality of communication paths for communicating between the overlapping wire rod layers. Additionally, a space is formed between the recess of one wire rod layer and another adjacent wire rod layer, allowing the plurality of communication paths to communicate with each other.

The invention relates to a method for producing a roof rack, to an extruded profile for use in a method of this nature and to a novel roof rack for a vehicle. The novel roof rack for vehicles consists of an extruded profile (1) of aluminum, wherein the rail (13) is formed by a tubular profile part of the extruded profile (1), and the end feet (11, 12) are formed from a bend section of the tubular profile part. The roof rack has different cross-sections in the longitudinal direction, which are created by machining of at least one additional profile web on the extruded profile (1). Freely selectable lateral contours (20, 20′) for a roof rack can be achieved in this way.

A steel wire which has an excellent fatigue limit when made into a spring is provided. A chemical composition of the steel wire according to the present embodiment consists of, in mass %, C: 0.53 to 0.59%, Si: 2.51 to 2.90%, Mn: 0.70 to 0.85%, P: 0.020% or less, S: 0.020% or less, Cr 1.40 to 1.70%, Mo: 0.17 to 0.53%, V: 0.23 to 0.33%, Cu: 0.050% or less, Ni: 0.050% or less, Al: 0.0050% or less, Ti: 0.050% or less, N: 0.0070% or less, Ca: 0 to 0.0050%, and Nb: 0 to 0.020%, with the balance being Fe and impurities. In the steel wire, a number density of V-based precipitates having a maximum diameter ranging from 2 to 10 nm is 500 to 8000 pieces/μm.sup.2.

A process to fabricate ultra-fine grain metal wire, comprising: inserting a plurality of metal strands into a flexible elastic polyurethane sheath having an accommodating slot for each of the strands of metal to form a sheathed strand assembly; equal channel angular pressing (ECAP pressing) the sheathed strand assembly through an ECAP die having a plurality of die channels corresponding to the plurality of metal strands. The process is designed to improve electric conductance and mechanical properties of elongated metal parts and is especially applicable to optimize the conductance and tensile strength of copper cables, wires, strings, and rods.