Subaru Impreza 2002 Service Manual page 2995

BRAKE
3) Measure the disc rotor thickness.
NOTE:
Make sure that a micrometer is set 5 mm (0.20 in)
inward of the rotor outer perimeter.
Disc rotor thickness: A (14 inch type)
Standard value
10 mm (0.39 in)
Service limit
8.5 mm (0.335 in)
Disc rotor thickness: A (15 inch type)
Standard value
18 mm (0.71 in)
Service limit
16 mm (0.63 in)
REAR DISC ROTOR
G4M0383
BR-36