Abstract: To manufacture a connecting rod including positioning grooves having a function of positioning a bearing metal at low cost. A big end part of a split type connecting rod is fractured in two after inserting an approximately cylindrical die into a bearing hole. The die has projections corresponding to locking grooves on an outer circumferential surface thereof. The die includes a pair of split dies having tapered faces, each expanding an opening on an edge of an end face of each of the split die halves. The tapered faces are formed by partially notching mating surfaces by pressing the inner circumferential surface of the bearing hole with the projections by a movement of the pair of split dies in a radial direction of the bearing hole.

Abstract: To manufacture a connecting rod including positioning grooves having a function of positioning a bearing metal at low cost. A big end part of a split type connecting rod is fractured in two after inserting an approximately cylindrical die into a bearing hole. The die has projections corresponding to locking grooves on an outer circumferential surface thereof. The die includes a pair of split dies having tapered faces, each expanding an opening on an edge of an end face of each of the split die halves. The tapered faces are formed by partially notching mating surfaces by pressing the inner circumferential surface of the bearing hole with the projections by a movement of the pair of split dies in a radial direction of the bearing hole.

Abstract: A method of improving wear-resistance and anti-seizing properties of slide surface of machineries, such as outer slide surfaces of piston pins of vehicle engines, wherein slide surfaces of iron or steel base materials of machineries are first processed carburizing, then the carburized surfaces are plated with chromium, and next the chromium-plated surfaces undergo impulses fine peening to produce lubricant-retaining cavities on the slide surfaces, which include fine cavities in the form of depressions in the chromium-plating layer and relatively large cavities produced by exfoliation of the chromium-plating layer.

Abstract: A microalloyed steel easy to separate by fracture splitting at low temperatures, which comprises from 0.15 to 0.35 wt % carbon, from 0.5 to 2.0 wt % silicon, from 0.5 to 1.5 wt % manganese, from 0.03 to 0.15 wt % phosphorus, from 0.01 to 0.15 wt % sulfur, from 0.01 to 0.5 wt % copper, from 0.01 to 0.5 wt % nickel, from 0.01 to 1.0 wt % chromium, from 0.001 to 0.01 wt % soluble aluminium, from 0.005 to 0.035 wt % nitrogen, from 0.001 to 0.01 wt % calcium, and from 0.001 to 0.01 wt % oxyge ough separation by fracture splitting at a low temperature, e.g., a connecting rod for engines.

Abstract: For the purpose of improving wear-resistance and anti-seizing property of slide surfaces of machineries, such as outer slide surfaces of piston pins of vehicle engines, slide surfaces of iron or steel base materials of machineries are first processed by carburizing, then the carburized surfaces are plated with chromium, and next the chromium-plated surfaces undergo impulses by shot peening to produce lubricant-retaining cavities on the slide surfaces, which include fine cavities in the form of depressions in the chromium-plating layer and relatively large cavities produced by exfoliation of the chromium-plating layer.

Abstract: A bearing metal positioning structure in a split connecting rod with lowered production cost and improved accuracy in positioning the bearing metal. The bearing metal positioning structure includes a pair of bearing metal halves, each of which is formed into a circular arc shape traversing 180 degrees. The pair of bearing metal halves have flat mating planes which abut one another to form a cylindrical bearing metal. A pair of projections are disposed on each of the mating planes at both axial ends so as to project radially outwardly therefrom. Locking grooves to be engaged with the pairs of projections, and additional locking grooves, are integrally die-formed simultaneously with the production of a die-formed body of the split connecting rod.