Showing specs for all NA & NB Miatas

Front brake disc minimum thickness — 255 mm rotor

18.0 mm (0.71 in)

Factory manualTaken from a Mazda factory workshop manual, with page citation.
Procedure

Applies only to a 255 mm outer-diameter front rotor; confirm the installed factory rotor size. Discard minimum and minimum after machining are separate limits. Machine on the vehicle; do not exceed the discard limit.

Applies to
  • NB 2001–2005 (BP-Z3) — Other years in this family inferred from 2005 factory evidence with owner approval; actual-year verification is separate.
  • Verified in: 2005 Mazda MX-5 Miata Workshop Manual (electronic manual capture)
Sources
  • 2005 Mazda MX-5 Miata Workshop Manual (electronic manual capture)Tier 1
    Page PDF p. 1282
    Printed: “Minimum Disk plate outer diameter 255 mm {10.0 in} 18.0 mm {0.71 in}”

Also in Additional factory manual gap audit