Brake rotor question

[Tim Rogers]

 "Brax Sisco"
> Car has 74000 miles, original rotors, first time pads have been replaced.<

Do you even use your brakes? ;-)

> The problem now is a rubbing, scraping sound brakes make at low speed
 stops.  Garage says rotor has a "hard spot" on it and needs to be
replaced.<

With use, pad material gets transfered to the disk, sometimes this happens
uneavenly and the pad grabs differently at that spot because of the
difference in the coeficient of friction at that spot.

>They said rotors are too thin to "turn" down.
Now, I thought brake pads were the wear item, and the rotors should last
a while.  Am I being lied to, or can 74000 miles wear the rotors down
that much?  Should I measure the rotor thickness?  What is the lower limit?<

It is quite possible to be so close to the wear limit on the rotors at 74K
miles that they can't be turned down without going under the limit.
Happened to my NX at around that mileage.
The minimum allowable rotor thickness is engraved on the outer edge of the
rotor.

Tim Rogers