CMM

Illustrated explanation

A gauge check and a measured coordinate serve different purposes

3CMM
A gauge check and a measured coordinate serve different purposesCallout 1: Thread gauge. Callout 2: Plain plug gauge. Callout 3: Coordinate probing. Thread gauges check their specified acceptance features, plain plug gauges check hole limits and a coordinate machine measures defined points. The inspection plan decides which checks are needed. Current term: CMM, callout 3. 1Thread gauge 2Plain plug gauge 3Coordinate probing
  1. Thread gauge

    The specified gauge assesses defined thread limits. One successful gauge check does not verify every dimension or sealing feature.

  2. Plug gauge

    A plain plug gauge checks the relevant bore limits. Use the correct GO or NO-GO procedure for that feature.

  3. CMMThis term

    A probe records defined surface coordinates. Measurement strategy and uncertainty determine how those points support a dimensional decision.

Thread gauges check their specified acceptance features, plain plug gauges check hole limits and a coordinate machine measures defined points. The inspection plan decides which checks are needed.

Conceptual inspection setups. Gauge type, calibration, temperature, decision rules and complete drawing requirements remain part of the actual inspection.

ReferencesISO 1502:1996 — Metric screw threads — Gauges and gaugingISO 5408:2009 — Screw threads — VocabularyISO 1938-1:2026 — Plain limit gauges of linear sizeISO 10360-2:2009 — Coordinate measuring machine performance tests