# Front brake disc after-machining thickness — 270 mm rotor

Canonical URL: https://miatatorque.com/spec/front-disc-after-machining-thickness-270mm-nb2/

Applicability: NB 2001–2005 (BP-Z3) — Other years in this family inferred from 2005 factory evidence with owner approval; actual-year verification is separate.; NB 2004–2005 (BP-Z3-TURBO, 6MT) — Common 2005 front-brake inspection covers both rotor sizes. Diameter-specific limits apply only to the rotor diameter named in the record; 2004 is inferred.

Confidence: fsm

20.8 mm (0.82 in)

Always confirm against your factory manual. Match every restriction and follow all stages and procedure notes. Disputed claims must not be automatically resolved. The complete record below preserves every printed unit, source claim and procedure.

```json
{
  "id": "front-disc-after-machining-thickness-270mm-nb2",
  "name": "Front brake disc after-machining thickness — 270 mm rotor",
  "aliases": [],
  "applies_to": [
    {
      "gen": "NB",
      "years": [
        2001,
        2005
      ],
      "engines": [
        "BP-Z3"
      ],
      "note": "Other years in this family inferred from 2005 factory evidence with owner approval; actual-year verification is separate."
    },
    {
      "gen": "NB",
      "years": [
        2004,
        2005
      ],
      "engines": [
        "BP-Z3-TURBO"
      ],
      "trans": [
        "6MT"
      ],
      "note": "Common 2005 front-brake inspection covers both rotor sizes. Diameter-specific limits apply only to the rotor diameter named in the record; 2004 is inferred."
    }
  ],
  "kind": "non-torque",
  "value_text": "20.8 mm (0.82 in)",
  "procedure": {
    "notes": "Applies only to a 270 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."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "fsm-2005",
      "page": "PDF p. 1282",
      "as_printed": "Minimum thickness after machining using a brake lathe on-vehicle\nDisk plate outer diameter 270 mm {10.6 in} 20.8 mm {0.82 in}",
      "verified_years": [
        2005,
        2005
      ],
      "document": {
        "id": "fsm-2005",
        "tier": 1,
        "title": "2005 Mazda MX-5 Miata Workshop Manual (electronic manual capture)",
        "covers": [
          {
            "gen": "NB",
            "years": [
              2005,
              2005
            ],
            "engines": [
              "BP-Z3"
            ]
          },
          {
            "gen": "NB",
            "years": [
              2005,
              2005
            ],
            "engines": [
              "BP-Z3-TURBO"
            ],
            "trans": [
              "6MT"
            ]
          }
        ]
      }
    }
  ],
  "jobs": [],
  "system": "brakes",
  "component": "gap-followup-2026-10",
  "componentName": "Additional factory manual gap audit",
  "sequence_diagrams": [],
  "url": "https://miatatorque.com/spec/front-disc-after-machining-thickness-270mm-nb2/"
}
```