Patent ID: 7014367

Claim:
An oil-impregnated sintered sliding bearing used for joints of a hydraulic excavator or joints for supporting a crane arm of a construction machine under a surface pressure of 6 kgf/mm 2 (58.8 MPa) or higher and at a sliding speed of 2 to 5 cm/s, which is made of a porous iron-based sintered alloy with quenched structure and said sintered alloy matrix contains martensitic structure and dispersion of copper phases, the content of copper is 15 to 25% by mass and the open porosity is 15 to 28%, wherein plurality of parallel ridge-and-groove lines having a height difference of 2 to 12.5 μm, extending in circumferential direction and a wavy surface in axial direction are formed by boring the bearing surface of said bearing, thereby the outer layer of said bearing surface being densified to the depth of 10 to 60 μm so as to block up the pore openings to 1 to 10% by area.