Between .008" and .010". Most rotors have very little wear but some sports cars use a brake pad that wears the rotors .030 to .040", those usually can only be machined once.
If I lived in the rust belt and only worked on cars that are 10 to 20 years old, I would be replacing a lot of rotors but I can’t in good conscience discard brake rotors from a car that is 18 months old with .090" of material above the minimum specs.
OK, few years back, off I went to AdvanceAutoParts and they pushed Wagner semi-metalics to me as “better than OEM”… which wore much faster than OEM with quite decent original rotors I had.
the next set I bought was Bendix “organic” from some internet source, was really happy with these.
I thought you possess some “secret/sacred knowledge” on this
We turn drums and rotors. And when I had my own place we turned them too. I can’t in good conscience sell a new rotor when the old one is still perfectly serviceable after being resurfaced. It takes 12 minutes to do a rotor, but while the lathe is cutting the tech will be cleaning and lubing the calipers, cleaning and adjusting the rears, changing fluid, etc. It really only adds minutes to the job, providing the last guy cleaned the grease off the lathe and hung the cones back where they belong.
Drums and rotors are expensive. Not all of them, but a quality rotor for a F250 Super Duty or even a Lexus can top $150. Resurfacing them for $30 each is in the best interest of the customer.
It’s been my experience that turning a rotor or drum in house often results in higher quality than some of the “white box” iron out there. I can’t remember a time when turning a rotor caused a comeback.
If I lived in a rust belt state I would imagine things might be different though.
If a job is done correctly but the price seems high I soon forget the price. However, if a job is not done right, no matter how cheap the price, I don’t forget it.i had to watch my pennies when we were starting out. Even then, it was cheaper in the long run to pay more for a quality job.
You mentioned above as I recall that they claimed to do more than just replace the front pads. $350 does seem a little pricey if that’s all they did. Some dealership shops will do an overall look-see at the car, looking for upcoming trouble spots, look for broken cv and steering boots, top off fluids, stuff like that, and charge a fixed fee for that. Maybe that’s what the extra $150 is for. I’ve always held to the opinion that if I’m charged for something that I don’t understand, to ask what it is for from the person charging me. Suggest you go back to the dealership and ask. Worse they can say is: It’s our policy. Best case, maybe they’ll realize they made a mistake and they’ll give you a $150 credit toward your next service. I sense you are sort of new to car ownership and repair and maintenance costs. If so, you’d serve yourself well to become familiar with the book “Popular Mechanics Complete Car Care”.
Actually, it had been several years since my last set of pads, so I was sure they were worn out, but I discovered they lasted pretty well. I changed them out anyway, because half the job was half done already by then.