A manufacturing method of a slinger, includes steps of: molding an annular blank material from a dull-finished steel sheet material through sheet metal press working or the like; and burring the blank material to mold a slinger. The values of the arithmetical mean roughness Ra of faces, of a burring mold, which individually come into contact with first and second slide-contact surfaces of the slinger, are set to 0.03 μm≤Ra≤0.07 μm. A ratio of pressure application force for holding the blank material between the faces to the 0.2% proof stress of the dull-finished material, is set to 1.0 or more and 1.53 or less. A clearance for the burring mold is set to T×(0.9 to 0.7) where “T” represents the sheet thickness of the blank material.

There is provided a method of manufacturing washers with improved material yield. The method includes: a preparing step of preparing a material having a panel shape; a first cutting-out step of cutting out a first thrust washer having a substantially arc shape from the material; and a second cutting-out step of cutting out a second thrust washer from a portion of the material in contact with a portion from which the first thrust washer is cut out.

There is provided a method of manufacturing washers with improved material yield. The method includes: a preparing step of preparing a material having a panel shape; a first cutting-out step of cutting out a first thrust washer having a substantially arc shape from the material; and a second cutting-out step of cutting out a second thrust washer from a portion of the material in contact with a portion from which the first thrust washer is cut out.

A method of manufacturing a washer capable of improving a material yield is provided. The method includes: a preparation step of preparing a longitudinal member which includes an upper crest portion and a lower crest portion formed on at least one of an upper surface and a lower surface of the longitudinal member, and an upper valley portion and a lower valley portion continuous to the upper crest portion and the rower crest portion in the right-left direction, respectively, the upper valley portion and the lower valley portion provided with projections, respectively; and a deformation step of deforming the longitudinal member such that the upper surface and the lower surface are arcuate as viewed in the direction from the front to the rear.

A method of manufacturing a washer capable of improving a material yield is provided. The method includes: a preparation step of preparing a longitudinal member which includes an upper crest portion and a lower crest portion formed on at least one of an upper surface and a lower surface of the longitudinal member, and an upper valley portion and a lower valley portion continuous to the upper crest portion and the rower crest portion in the right-left direction, respectively, the upper valley portion and the lower valley portion provided with projections, respectively; and a deformation step of deforming the longitudinal member such that the upper surface and the lower surface are arcuate as viewed in the direction from the front to the rear.

A steel material is heated and punched while tension is applied to the steel material (2) in at least one direction along a surface of the steel material between first and second portions of the steel material distant from each other with forming unit posed therebetween. The tension is applied to increase a distance between the first and second portions of the steel material by a length corresponding to an amount by which the distance between the first and second portions of the steel material thermally expands as the steel material is heated to the temperature in the step of heating and punching. The forming unit includes a first die for punching the steel material and a second die facing the first die, the first die or the second die having a forming surface having a concave curved surface.

A steel material is heated and punched while tension is applied to the steel material (2) in at least one direction along a surface of the steel material between first and second portions of the steel material distant from each other with forming unit posed therebetween. The tension is applied to increase a distance between the first and second portions of the steel material by a length corresponding to an amount by which the distance between the first and second portions of the steel material thermally expands as the steel material is heated to the temperature in the step of heating and punching. The forming unit includes a first die for punching the steel material and a second die facing the first die, the first die or the second die having a forming surface having a concave curved surface.

A manufacturing method of a slinger, includes steps of: molding an annular blank material from a dull-finished steel sheet material through sheet metal press working or the like; and burring the blank material to mold a slinger. The values of the arithmetical mean roughness Ra of faces, of a burring mold, which individually come into contact with first and second slide-contact surfaces of the slinger, are set to 0.03 mRa0.07 m. A ratio of pressure application force for holding the blank material between the faces to the 0.2% proof stress of the dull-finished material, is set to 1.0 or more and 1.53 or less. A clearance for the burring mold is set to T(0.9 to 0.7) where T represents the sheet thickness of the blank material.

A washer that includes: an inner peripheral face formed in an arc shape; an outer peripheral face formed in an arc shape concentric with the inner peripheral face on a radially outer side of the inner peripheral face; and outer peripheral cut-out portions (such as a left outer peripheral cut-out portion and a right outer peripheral cut-out portion) formed at positions of the outer peripheral face corresponding to end portions (a first end portion and a second end portion) of the inner peripheral face to have the same shapes as outside shapes of the corresponding end portions of the inner peripheral face.

A washer that includes: an inner peripheral face formed in an arc shape; an outer peripheral face formed in an arc shape concentric with the inner peripheral face on a radially outer side of the inner peripheral face; and outer peripheral cut-out portions (such as a left outer peripheral cut-out portion and a right outer peripheral cut-out portion) formed at positions of the outer peripheral face corresponding to end portions (a first end portion and a second end portion) of the inner peripheral face to have the same shapes as outside shapes of the corresponding end portions of the inner peripheral face.