Well with out a specific year and model that is hard to answer to the letter.However for example a b2000 (1986) min thickness is 18.00(0.7480) max is 0.04(0.0016)Next b2200 87-89 minimum 18.00(0.709) max is 0.0015(0.0016).B2600 minimum is 20.00(0.787) max run out 0.015(0.0016).Keep in mind the MAX is run out.I honestly will say buying NEW is better than resufacing due to cost these days.I can buy a new set for my 87 b2200 for around 25.00 each and no machine shop trip and less time involved with the work.Hope this helps and being more specific on model and year helps better answer this.
8mm
For a 1998 Mazda 626 the minimum thickness is .866 inches for the front rotor and .315 inches for the rear rotor. This is the same for the 4 and 6 cylinder versions.
23mm front 9mm rear
2004 ford explorer minimum rotor thickness
Front Rotor Minimum Thickness after machining the rotor is .996
The 2001 Pontiac Grand Am minimum brake rotor thickness is .075. The minimum brake rotor thickness is a standard minimum. Certified mechanics cannot use the brake rotor when the thickness drops below this level.
The minimum thickness should be cast somewhere on the rotor.
The minimum front brake rotor thickness is three aids of an inch. When the rotor does not have the minimum thickness the auto mechanic replacing the brakes can not use the rotor.
Thea minimum thickness for a 1996 Toyota Corolla rotor is .787, measured in In thousandths of an inch. Anything rotor that does not meet this minimum thickness should be discarded.
Front: 24mm new, 22mm minimum Rear: 10mm new, 8mm minimum
The minimum thickness is cast into the rotor, either on the edge of the rotor or into the rotor hub.
I use a micrometer the rotor should have minimum thickness stamped on the rotor is inches or millimeters