[530i] Rotor thickness specs and measuring

[quattro PETE]

Does anyone know these specs for front and back rotors: minimum thickness and new thickness?

Also, do local auto part stores sell relatively inexpensive tools to measure rotor thickness?

[thejlevie]

Minimum thickness is 28.4mm (1.12in) front and 18.4mm (0.72in) rear. You can make a neat thickness tool from a pair of cheap plastic calipers by cutting away part of the jaws so they'll clear the ridge.

A simple check is to compare the thickness of the ridge with a dime. If about the same you need new rotors. And in most cases, if you need new pads you'll need new rotors.

[quattro PETE]

Thank you. So, considering that new rotors are 30mm and 20mm thick, respectively, there is only 1.6 mm worth of thickness to be used. Interesting.

I just did the dime test - looks like I'll need new rotors pretty soon. How much do people get out of their rotors (I know it varies depending on your driving style and hwy/city split)? Mine have 39k miles.