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

http://img.photobucket.com/albums/v160/hot66/BMW/A41DBC4F-1986-4BC9-A77D-B0114BCD29A0_zpsojkgdemt.jpg (http://s.photobucket.com/user/hot66/media/BMW/A41DBC4F-1986-4BC9-A77D-B0114BCD29A0_zpsojkgdemt.jpg.html)

[73CSL]

Ignore the wear sensor bit, just read it's only on the drivers side and it's the passenger side that's down to metal

[73CSL]

Just read 26.4mm is the limit on standard m3, so looks like new disc are needed