A system and method of fabricating a percussion tool that includes one or more surfaces modified using the ferritic nitrocarburization process. The percussion tool includes a piston positioned in sliding contact within a casing. The piston includes an inner wall and an outer wall, where the inner wall defines a passageway extending longitudinally therethrough. The outer wall is positioned in close fitting relationship with an internal surface of the casing. One or more surfaces of at least one of the casing's internal surface and/or the piston's outer wall are modified using the ferritic nitrocarburization process.

A system and method of fabricating a percussion tool that includes one or more surfaces modified using the ferritic nitrocarburization process. The percussion tool includes a piston positioned in sliding contact within a casing. The piston includes an inner wall and an outer wall, where the inner wall defines a passageway extending longitudinally therethrough. The outer wall is positioned in close fitting relationship with an internal surface of the casing. One or more surfaces of at least one of the casing's internal surface and/or the piston's outer wall are modified using the ferritic nitrocarburization process.

A sliding spline shaft device of the present invention includes a male spline and a female spline that is fitted to the male spline in an axially slidable manner, and at least one of the splines has a surface processed layer. The surface processed layer includes an undercoat layer, an intermediate layer containing phosphate, and a topcoat layer containing solid lubricant, in this order. The undercoat layer contains iron nitride and/or iron carbide. Thus, the surface of a base material has high hardness. As a result, microscopic deformation of the sliding surface is reduced, and increase in a real contact area is suppressed, whereby stick-slip is prevented.

A gripping tool for gripping oilfield tubulars includes a gripping element having a substrate, and at least one gripping surface configured to engage an oilfield tubular, the at least one gripping surface being formed on the gripping element. The at least one gripping surface includes a coating on an outer surface of the substrate, the coating includes a carrier and a plurality of particles at least partially embedded in the carrier. The particles each have a hardness that is greater than a hardness of the carrier and a base metal of the gripping element, and the particles extend outward from the carrier and are configured to engage a structure that is gripped by the gripping tool.

A number of variations may include a ferritically nitrocarburized vehicle component comprising a compound zone and a friction surface at an outer edge of the compound zone wherein the friction surface is configured for engagement with a corresponding friction material, and wherein the compound zone comprises a nitride layer comprising epsilion iron nitride, Fe.sub.3N and gamma prime iron nitride Fe.sub.4N.

An electric power steering device includes an input shaft, an output shaft, a torsion bar provided at an inner diameter side of the input shaft and the output shaft with coaxially coupling the input shaft and the output shaft each other; and, a torque detection sleeve which is arranged at an outer diameter side of the torque detection encoder part, and of which a rear end portion is externally fitted and fixed to the fitting part. A nitride layer is formed at least at a part, at which the torque detection encoder part is formed, of the outer peripheral surface of the output shaft.

An electric power steering device includes an input shaft, an output shaft, a torsion bar provided at an inner diameter side of the input shaft and the output shaft with coaxially coupling the input shaft and the output shaft each other; and, a torque detection sleeve which is arranged at an outer diameter side of the torque detection encoder part, and of which a rear end portion is externally fitted and fixed to the fitting part. A nitride layer is formed at least at a part, at which the torque detection encoder part is formed, of the outer peripheral surface of the output shaft.

A guiding member, having a body provided with a bore for mounting a mobile element is presented. The body consists of a metallic material. The bore has a surface layer treated against jamming over a diffusion depth of less than or equal to 0.6 mm. The surface layer has a hardness of greater than or equal to 500 Hv1 over a depth of between 5 and 50 ?m.

A guiding member, having a body provided with a bore for mounting a mobile element is presented. The body consists of a metallic material. The bore has a surface layer treated against jamming over a diffusion depth of less than or equal to 0.6 mm. The surface layer has a hardness of greater than or equal to 500 Hv1 over a depth of between 5 and 50 ?m.

A sliding member (1) includes an iron and steel-based sintered compact containing chromium, molybdenum, and carbon and having a content of chromium, of 5 mass % or less. The sliding member (1) includes: a compound layer (11) which has a sliding surface (1a) and is formed mainly of an iron and steel nitride; and a diffusion layer (12) which is adjacent to the compound layer (11) and has an iron and steel structure into which nitrogen and carbon diffuse. The concentrations of carbon and nitrogen in the diffusion layer (12) are gradually reduced with increasing depth from the sliding surface (1a).