Sintered bearing

A sintered bearing having, in an inner periphery, a bearing surface that forms a bearing gap between the bearing surface and a shaft to be supported, wherein

• the sintered bearing has a radial crushing strength greater than or equal to 300 MPa,
• the sintered bearing is made of 10 to 30 mass % of Cu, 0.5 to 3.0 mass % of Sn and 0.3 to 1.5 mass % of C, with the balance being iron and inevitable impurities,
• the sintered bearing has an iron structure and a copper structure, the iron structure and the copper structure being formed by sintering a partially diffusion-alloyed powder having an average grain size less than or equal to 106 μm,
• the iron structure is substantially covered with a plurality of copper structures comprising a bronze phase, and an average grain size of each of the copper structures covering the iron structure is smaller than an average grain size of the iron structure,
• the iron structure has a porous structure formed by sintering a reduced iron powder,
• a lubricating oil is retained in pores formed in the iron structure, and
• the sintered bearing has an oil content greater than or equal to 15 vol %.