Wear limit on front discs ?

[73CSL]

Trying to work out if I need new discs or not.

If I've measured the disc accurately, I think they are 25mm thick as they currently stand. What's the recommended wear point for changing ?

Also one of my pads has worn to the metal ( appears the green wear indicator wire has been tucked up out of the way and not in use) and just started to mark the inner disc surface