Hyundai GENESIS COUPE BK 2010 Manual page 218

Standard (New): 0.05mm (0.0019in.) max
Service limit: 0.08mm (0.0031in.)
6. Check the mica depth (A). If the mica is too high (B), undercut the mica with a hacksaw blade to the proper depth.
Cut away all the mica (C) between the commutator segments. The undercut should not be too shallow, too narrow,
or v-shaped (D).
Commutator mica depth
Standard (New) : 0.7 mm (0.0275in.)
Limit : 0.2mm (0.0079 in.)
7. Check for continuity between the segments of the commutator. If an open circuit exists between any segments,
replace the armature.
8. Check with an ohmmeter that no continuity exists between the commutator (A) and armature coil core (B), and
between the commutator and armature shaft (C). If continuity exists, replace the armature.