New disc thickness is 17.5mm. Don't know of a spec for minimum thickness. Usually replace when groove pattern is about gone.
That's for a 5F7048 disc.
Thanks, Where did you find that spec? It would be nice to be able to look stuff like that up myself. I will check my disc tomorrow and see what it is at, I only have about 2 turns of adjustment left before the adjuster will bottom out. I lock it by hand on the bench and tighten as tight as I can by hand until the disc won't move, then I unlocked and it has about 2.25 turns left until it bottoms out, it seems like that is not much left before the disc would be totally worn out and slip all the time. Any thoughts?