# Rear brake disc after-machining thickness

Canonical URL: https://miatatorque.com/spec/rear-disc-after-machining-thickness-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.

Confidence: fsm

8.4 mm (0.33 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": "rear-disc-after-machining-thickness-nb2",
  "name": "Rear brake disc after-machining thickness",
  "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."
    }
  ],
  "kind": "non-torque",
  "value_text": "8.4 mm (0.33 in)",
  "procedure": {
    "notes": "Keep the discard limit separate from minimum after machining; machine with the disc installed on the vehicle. This record does not establish a Mazdaspeed rear-disc limit."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "fsm-2005",
      "page": "PDF p. 1270",
      "as_printed": "Minimum thickness after machining by using a brake lathe on-vehicle:\n8.4 mm {0.33 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/rear-disc-after-machining-thickness-nb2/"
}
```