Abstract: In a webbing take-up device, side faces of press-fit holes in a pinion are inclined in directions toward the outside of the press-fit holes on progression toward the right. Press-fit portions of a torsion shaft are press-fit into the press-fit holes from the right such that an interference force between the press-fit portions and the side faces of the press-fit holes increases on progression toward the left. This enables the press-fit portions to be effectively retained in the press-fit holes.

Abstract: A method for producing a surface-hardened material, comprising: an immersion step of immersing an iron steel material having nitrogen attached in the form of a solid solution on the surface thereof in a melt containing a chloride at a temperature ranging from 650° C. to 900° C.; and a cooling step of cooling the immersed iron steel material to a temperature equal to or lower than a martensitic transformation start temperature at a cooling rate equal to or higher than a lower critical cooling rare at which martensitic transformation starts.

Abstract: A method for producing a surface-hardened material, comprising: an immersion step of immersing an iron steel material having nitrogen attached in the form of a solid solution on the surface thereof in a melt containing a chloride at a temperature ranging from 650° C. to 900° C.; and a cooling step of cooling the immersed iron steel material to a temperature equal to or lower than a martensitic transformation start temperature at a cooling rate equal to or higher than a lower critical cooling rare at which martensitic transformation starts.

Abstract: In a webbing take-up device, side faces of press-fit holes in a pinion are inclined in directions toward the outside of the press-fit holes on progression toward the right. Press-fit portions of a torsion shaft are press-fit into the press-fit holes from the right such that an interference force between the press-fit portions and the side faces of the press-fit holes increases on progression toward the left. This enables the press-fit portions to be effectively retained in the press-fit holes.

Abstract: A method for producing an iron base material having a coating includes forming a Ni—Cr—Si corrosion-resistant alloy coating film by a combination of composite plate processing with a Ni solution containing Cr and Si, and a heat treatment after the composite plate processing, wherein the Ni—Cr—Si corrosion-resistant film contains Ni, Cr, and Si, and wherein a content ratio of Cr is 1 to 50 wt % of the alloy coating film, a content ratio of Si is 0.1 to 30 wt % of the alloy coating film, and the alloy coating film has a thickness of 0.1 to 1000 ?m, the composite plate processing forms a composite plating film, in which a chromium silicide particle selected from Cr3Si, Cr5Si3, Cr3Si2, CrSi and CrSi2 is co-deposited in a Ni matrix, and the heat treatment at 600° C. or higher decomposes and solid-solubilizes 50% or more of the chromium silicide particle in the Ni matrix.

Abstract: A highly corrosion-resistant alloy coating film on the surface of a metallic material by a low-cost and mass-producible simple formation method including forming a corrosion-resistant alloy coating film on the surface of a metallic material, the film contains Ni, Cr, and Si as essential constituents, in which the content ratio of Cr is 1 to 50 wt %, the content ratio of Si is 0.1 to 30 wt %, and the film has a thickness of 0.1 to 1000 ?m.