| 摘要 |
Nose sprocket for chain saws, comprising a body of substantially uniform thickness, towards the center limited by a bearing race (13) and at the periphery provided with teeth (11) to carry a saw chain, characterized by having a solid low-friction coating deposited from gas phase except on the bearing race (13) and the inner parts (15) of the sprocket body surfaces adjoining the bearing race, said coating comprising multiple sub-layers of graphite and tungsten carbide. The coating having a total inclusive thickness of 1 micron or more on each side. Method for producing a low-friction coating on selected parts of the surface of a nose sprocket for chain saws, characterized by the coating being deposited from gas phase, and by masking a central limiting surface (13) which is to be used as a bearing race as well as the adjoining inner parts (15) of the side surfaces during deposition. <IMAGE>
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