Image Number 8 for United States Patent #6457566.
A brake rotor for a vehicle is provided with one or more visual wear indicators on brake contact surfaces to allow easy visual inspection of brake rotor condition without the need for measurement tools. The inventive visual wear indicator system is not obtrusive and as such removes only a relatively small amount of brake contact surface to form a recessed surface at a depth of a predetermined minimum useable rotor thickness. With this inventive rotor, one can visually inspect the condition of a brake rotor and readily determine whether the rotor requires replacement or remachining. The visual wear indicator is provided on a brake contact surface of the rotor solely within a brake contact region so as to provide an accurate reflection of the condition of the rotor in areas where wear will occur. The visual indicator may be provided on only one, but preferably both, sides of the rotor and may take numerous forms, such as a cylindrical bore, a more complex shape, an annular groove or even an eccentric groove. For additional visibility, the visual wear indicator may be colored for additional contrast. The visual wear indicator may also be coated to prevent rusting.