No not warped but a pitted contact patch from standing and some inline grooves from 2 pad life cycles...so took 1 mm of each face to be completely smooth.
My work mates done it for me 1 was a RN engineer and the other a tool maker so between them they made up a boss to hold the disc and set it up with 1 thou runout before facing off. Lost some depth to the j hook groove.
Obviously with competition like this im the best looking engineer on my shift lol.
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