i am looking to get my rotors grinded/turned to take some of the grooves and marks out of them while replace the pads with OEM pads (the PO used cheap pads). i was wondering what are the thinnest you can have your rotors before you need to throw them out. thanks

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198? 300D ???K - Future DD
1989 300TE 285K - traded in '12
1984 300SD 186K - Sold in 08
1978 300SD 330K - Died in 05