Abstract: The high-strength race of the present invention comprises using A steel for a high-strength race comprising the following elements in percentage by weight: C: 0.30 to 0.60%, Si: 0.30 to 1.30%, Mn: 0.5 to 1.5%, B: 0.0050% or less, Cr: 0.1 to 0.5%, Mo: 0.1 to 0.5%, Si+Mo: 0.5 to 1.4%, Ni: 0.02 to 1.0%, the balance of Fe and unavoidable impurities, performing induction hardening to make the race have a surface hardness of 58 HRC or more and further a surface hardness of 52 HRC or more even after the surface is tempered at 300° C. The high-strength race is superior in rotating fatigue properties, anti-surface fatigue strength and productivity by a combination of composition control and induction hardening.

Abstract: A sliding structure including first and second sliding elements made of metal and including first and second sliding surfaces relatively slidable via a lubricating oil film therebetween, in which at least one of the first and second sliding surfaces having a microscopic surface structure including a base portion, dimples inward recessed from the base portion and separated from one another, and a peripheral portion defining the opening area of each of the dimples and extending along a periphery of each of the dimples. A ratio of a sum of opening areas of the dimples to an area of the at least one of the first and second surfaces is in a range of 5% to 60%. The peripheral portion has a height smaller than a thickness of the lubricating oil film.

Abstract: A sliding structure including first and second sliding elements made of metal and including first and second sliding surfaces relatively slidable via a lubricating oil film therebetween, in which at least one of the first and second sliding surfaces having a microscopic surface structure including a base portion, dimples inward recessed from the base portion and separated from one another, and a peripheral portion defining the opening area of each of the dimples and extending along a periphery of each of the dimples. A ratio of a sum of opening areas of the dimples to an area of the at least one of the first and second surfaces is in a range of 5% to 60%. The peripheral portion has a height smaller than a thickness of the lubricating oil film.

Abstract: The high-strength race of the present invention comprises using A steel for a high-strength race comprising the following elements in percentage by weight: C: 0.30 to 0.60%, Si: 0.30 to 1.30%, Mn: 0.5 to 1.5%, B: 0.0050% or less, Cr: 0.1 to 0.5%, Mo: 0.1 to 0.5%, Si +Mo: 0.5 to 1.4%, Ni: 0.02 to 1.0%, the balance of Fe and unavoidable impurities, performing induction hardening to make the race have a surface hardness of 58 HRC or more and further a surface hardness of 52 HRC or more even after the surface is tempered at 300° C. The high-strength race is superior in rotating fatigue properties, anti-surface fatigue strength and productivity by a combination of composition control and induction hardening.