brake rotors, rotors, machine rotors, rotor resurfacing, powerstop

Rotor Resurfacing/Machine Rotors

Brake rotors lose some thickness little by little whenever brakes are applied. People machine rotors to extend rotors life. There are downsides, though. Machining can lead to poorer quality rotors and safety issues, is time consuming, and can be difficult to do correctly.

Can You Resurface Drilled and Slotted Rotors?

You can cut or machine a drilled and slotted rotor. Just set your brake lathe to its slowest setting to avoid any chatter. Whenever replacing your pads, you’ll want to replace or cut your rotors, so the new pads can bed-in properly. However, if you want that non-directional cross-cut finish go with a new set of rotors from PowerStop. It’s likely to cost close to the same, and even possibly less than cutting a rotor.

What is Machining Rotors?

Machining rotors can gain back some friction on worn rotors and reduce run-out. Some people even resurface rotors a couple times before rotor replacement. The machining process usually start with sanding the rotors with 120 grit sandpaper to get rid of build-up deposit and dirt. Then cutting, thinning, and trimming the surface of rotors, also known as resurfacing. Finally, testing. Test drive the vehicle to see if the rotors gained some friction back.

Why do people machine rotors?

  • Can gain back friction and stopping power
  • Can extend rotor operational life
  • Reduces run-out on new rotors

4 reasons why resurfacing rotors is concerning?

  1. Reduces rotor quality
  2. Cost and time
  3. Safety
  4. Hard to resurface rotors properly


Reason 1: Quality

  • Machining rotors make them thinner, susceptible to warping
  • Machining pushes the rotor thickness to the limit
  • Thin rotors lead to overheating, warping, vibrating, etc.
  • When the rotor thickness is different, it results in imbalance, weight shifting, shaking, and vibrating

Reason 2: Cost and time

  • The cost to machine rotors might be greater than just replacing new rotors
  • Need to machine both rotors (a full set) to avoid imbalance
  • Machining rotors might take a couple hours at the repair shop


Reason 3: Safety

  • Rotor weight needs to be evenly distributed or else it leads to shaking and vibrating
  • It takes as little as .001 inches difference in thickness to notice when driving and braking
  • If rotors are machined too thin, they can warp and damage brake parts
  • By machining the rotors to the maximum level, rotors will overheat, fade, and lose stopping power

Reason 4: Not getting rotors resurface properly

  • Some repair shops may resurface rotors as fast as possible. This can lead to mistakes in the process or too much metal being shaved off.
  • Using worn bits to machine rotors may result in vibration
  • Rotor vibration due to trimming metal off rotors


  • Depending on the rotor condition, replacing rotors is a better option than resurfacing
  • Check out PowerStop’s high-quality performance brake kits and rotors! Do it yourself, replace your own rotors to save money or bring PowerStop’s rotors to a reliable repair shop.


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