Brake Disc Minimum Thickness

It is stamped on the disc. Measure with a micrometer. A lip on the edge shows wear. Machining a disc reduces its thickness, so it is only possible if enough material remains. Rear discs on cars with electronic parking brakes can corrode on the inner face when rarely used, which also shortens their life. Always replace discs and pads in pairs on the same axle.

Thin discs overheat and lose strength.

Replace discs below the limit. New pads often need new discs.