EBC Automotive brake rotors are made from G3000 spec cast iron and full specifications and properties can be seen here!
Runout figures above this will lead to vibration after 3000 to 4000 miles due to what we call disc thickness variation (wearing a thin spot on the high point of the rotor as it runs off-true) which is not a warranty condition.
So you see this is no cheap import brake disc. These brake discs have the highest integrity and product quality on the aftermarket. An OE quality replacement disc, made of the finest grade iron and a perfect replacement disc for any car.
Every EBC rotor is runout inspected on this machine. Even when manufactured on state of the art precision machines, not even ONE single disc escapes this process guaranteeing perfect disc alignment. If during install you notice runout on your car it will surely be due to a chassis alignment that happens on one in seven cars, usually cased by nudging a curb or hitting a pothole in the road earlier in driving the vehicle. This is ONLY cured by aligning the rotors on a Pro Cut lathe and how to achieve that is explained HERE