DEMO — fictional range. Local brief only, NOT SENT. No personal data is collected or transmitted.
INSPECTION
A first article is measured from a named reference.
A first article report is a measurement of one part against one drawing. Its value depends entirely on whether the drawing named the reference the measurements were taken from.
Illustrative inspection checklist
- Material certification
- Traceable to the specific heat or batch supplied
- First article report
- Every dimension on the drawing, measured and recorded
- Datum statement
- Which feature the measurements were taken from
- Critical feature
- The dimension the assembly actually depends on
- Concentricity or position
- Measured against the named datum, not against an edge
- Surface finish
- Measured on the delivered part rather than the sample
- Deburring
- Edges broken as drawn, checked on the part
- Marking
- Part number, lot and material legible on the part itself
An illustrative checklist for a fictional range. A real programme defines the tolerance, the sampling method, the inspection window and the remedy if a batch fails.
The four things a programme needs in writing.
The tolerance, the sampling method, the window in which inspection happens, and what happens if the batch fails. Without all four, a failed delivery becomes an argument rather than a process.
Why the datum statement is on the report.
Because a measurement without its reference cannot be checked by anyone else. Two reports can disagree while both being correct, if they were taken from different features.