Abstract: A probe unit comprising a base in the form of a rectangular plate and a plurality of ultrathin metal wires which are partially secured to the base at a given pitch. Each of the wires comprises a straight portion firmly secured to the base, a bent portion located on an extension of the straight portion, and an inclined portion inclined from the bent portion outwardly of the base toward an inspected surface of an object to be inspected, and an R-shaped portion extending from the front end of the inclined portion outwardly of the base. The bent portion protrudes outwardly from the base and is bent toward the inspected surface. The R-shaped portion forms each probe pin bearing against the inspected surface.

Abstract: A carbon fiber prepreg comprising a unit layer consisting of carbon fibers and a matrix resin layer, and stranded filaments or single filaments incorporated thereinto. The steel fiber is an Ni plated low-carbon dual-phase steel filament and has a filament diameter of not more than 100 .mu.m, a tensile strength of 300 to 700 kgf/mm.sup.2, and an area reduction at fracture of more than 20%. The carbon fibers and steel filaments are aligned codirectionally, and the steel fiber content of the prepreg relative to the carbon fiber is not more than 10 vol %. Sheets of the carbon fiber prepreg are laminated to form a carbon fiber reinforced composite.

Abstract: High strength low carbon steel wire rods excellent in the cold drawing property have a composite structure in which an acicular low temperature transformation phase comprising a martensite, bainite and/or the mixed structure thereof that comprises, by weight %,C: 0.02-0.30%,Si: less than 2-5%,Mn: less than 2.5% andthe balance of iron and inevitable impurities and that may partially contain retained austenite is uniformly dispersed at the volume ratio of from 10 to 70% in the ferrite phase, and in which the weight of (C+N) in solution the ferrite phase is less than 40 ppm.

Abstract: A catheter guide wire which, despite its reduced diameter, exhibits improved strength and resistance to corrosion by body fluids and medicines. The catheter guide wire 10 is composed of a stainless steel core wire 11, a winding of a low carbon duplex structure steel wire 13 having a diameter smaller than 30 .mu.m and a tensile strength higher than 300 kgf/mm.sup.2, said winding covering the core wire such that tiers of the low carbon duplex structure steel wire run obliquely to the axis of the core wire 11 and have turns crossing each other, and a polyester resin film 15, thinner than 3 .mu.m, covering the low carbon duplex structure steel wire 13. The catheter is composed of a resin inner tube and a low carbon duplex structure steel wire 13 covered with a polyester resin film 15, which runs around the resin inner tube obliquely to the axis and crosses each other.

Abstract: A fishing line composed of a strand of a plurality of steel wires twisted together and coated with synthetic resin, wherein the steel wire is a low carbon duplex structure steel wire in the fibrous fine metallic structure having a tensile strength of 300 to 600 kgf/mm.sup.2 and coated by plating with anticorrosive metal on the outer surface, the twist pitch of the strand being 13 to 20 times the diameter thereof and the thickness of coating layer of synthetic resin being 4 .mu.m or more. This fishing line is high in tensile strength and knot strength, and is hardly kinked or curled when subjected to impact.

Abstract: An inspection probe which allows a plurality of such inspection probes to be arranged at a remarkably reduced pitch. The inspection probe comprises a very thin metal wire having a diameter of 120 .mu.m or less and so shaped as to have self resiliency, and a plated noble metal layer formed on a surface of the very thin wire. A probe pin head for the inspection of an electronic circuit board is constructed employing a plurality of such inspection probes. The inspection probes are secured to or embedded in a base made of a resin material. A process of producing the probe pin head is also disclosed.

Abstract: A coaxial cable having an inner conductor including a very fine metal wire having a diameter of 120 .mu.m or below and a tensile strength of 100 kg/mm.sup.2 or above, and a plated noble metal layer coating the very fine metal wire, an insulating layer of an insulating material coating the inner conductor, an outer conductor coating the insulating layer, and a jacket coating the outer conductor. In forming the inner conductor, a metal wire is coated with a noble metal layer by plating, and then the metal wire coated with the noble metal layer is subjected to plastic working to reduce the diameter and to improve the structure of the noble metal layer, A high-frequency signal applied to the coaxial cable is transmitted through the noble metal layer of a satisfactory structure by skin effect without being disturbed. The very small diameter and very high tensile strength of the very fine metal wire of the inner conductor enables the coaxial cable to be formed in a very small diameter.

Abstract: High strength low carbon steel wire rods excellent in the cold drawing property have a composite structure in which an acicular low temperature transformation phase comprising a martensite, bainite and/or the mixed structure thereof that comprises, by weight %,C: 0.02-0.30%,Si: less than 2.5%,Mn: less than 2.5% andthe balance of iron and inevitable impurities and that may partially contain retained austenite is uniformly dispersed at the volume ratio of from 10 to 70% in the ferrite phase, and in which the weight of (C+N) in solution in the ferrite phase is less than 40 ppm.

Abstract: High strength low carbon steels having good ultraworkability which comprises 0.01-0.3 wt % of C, below 1.5 wt % of Si, 0.3-2.5 wt % of Mn and the balance of iron and inevitable impurities. In the steel, a low temperature transformation product phase consisting of acicular martensite, bainite or a mixed structure thereof is uniformly dispersed in a ferrite phase in an amount by volume of 15-40%. Wire articles of these steels and methods for making the steels are also disclosed.

Abstract: A high-strength, high-toughness steel with good workability is produced by working a steel containing 0.005-0.3% C and 0.3-2.5% Mn and optionally up to 1.5% Si, in the course of hot working thereof, at temperatures within the range of from the Ar.sub.3 point to 930.degree. C. or to 980.degree. C. (for a steel containing Nb, V, Ti and/or Zr) at an area reduction rate of at least 30%, and, in the course of cooling, rapidly cooling the steel in the ferrite phase precipitation temperature range when the ferrite phase has occupied 5-65% or 5-60% (for a steel with Si and/or Nb, V, Ti and/or Zr) of the steel, whereby a two-phase structure comprising ferrite and martensite is produced.