Key takeaways
- A first article report is only useful when every measured feature traces to a ballooned drawing revision.
- The material certificate should name the full grade and the lot, not just the family name.
- A contact needs joint evidence: a cross-section and a strength test, because the bond is hidden after assembly.
- Keep the signed pack with the first production lot so later changes can be measured against it.
What a contact FAI is for
A first article inspection is a check that the process can make the drawing at the start of a programme. It is not a life test and it is not a type test. It records the first parts made with production tooling, production material and production settings, then compares every characteristic with the drawing.
For a contact, the pack has to do more than a sheet of dimensions. A contact is a composite part with a material joint and an electrical duty. A dimensional report that leaves out the joint and the resistance reading describes the shape but not the part.
The drawing and the balloon map
The drawing is the spine of the pack. Every characteristic in the report should carry a balloon number that matches the drawing revision. If the drawing has a general tolerance in the title block, apply it and state which class. If a dimension is basic, the report should show the GD&T result, not a simple linear measurement.
A common weakness is a report that measures the easy features and summarises the rest as within tolerance. That tells the reader nothing. Each row should show the nominal, the tolerance, the measured value and the pass or fail decision. For a contact, the critical rows usually include head diameter, head height, face radius, shank diameter, shank length, bond-line position and any concentricity call.
Material certificates for two materials
A composite contact needs two certificates, one for the head and one for the shank. Each should name the grade, the lot or heat number, the supplier and the chemistry. For the head, the designation should include the oxide system, not only the silver content. For the shank, the temper and the plating specification belong on the record.
A mill certificate proves what the mill supplied. It does not prove that the certificate belongs to the strip or wire that made the part. The link is the lot number on the certificate, the lot number on the material label and the lot number on the production record. If those three do not match, the pack has a traceability gap, even when the chemistry is correct.
A certificate of conformity is a statement, not a test. It is useful for a commodity item, but it should not replace a chemistry check on a contact material where the grade decides the switching duty.
A certificate is a claim about a lot
The value of a material certificate is the link between the lot it describes and the parts in the box. Without that link, the chemistry may be correct and still belong to another batch.
Joint evidence
The joint between the head and the shank is hidden after assembly. The pack has to show it before it disappears. A cross-section through the axis, polished and etched, shows whether the bond is continuous, whether there are voids or oxide inclusions, and whether the shank grain flow is sound.
Add a strength test that matches the joint. A shear test on the bond and a pull test on the staked assembly are different checks, and a contact may need both. State the sample size, the test speed and the failure mode. A result with no failure location cannot be compared with the next build.
For a staked rivet, include the carrier. The pull-out strength depends on the blade thickness, the hole size and the clinch form, so a rivet tested in a substitute fixture is not evidence of the production joint.
The pack at a glance
The table below sets out the evidence a contact pack should contain. It is a minimum for a new part. A safety-related contact may need more, and the drawing owner should say so at the quotation stage rather than after the first article.
| Item | Evidence | What it proves |
|---|---|---|
| Ballooned drawing | Current revision with every characteristic numbered | The report and the drawing describe the same part |
| Dimensional report | Nominal, tolerance, measured value and decision for each row | The process can hold the drawing |
| Head certificate | Grade, oxide system, lot, chemistry and supplier | The contact face is the material that was ordered |
| Shank certificate | Alloy, temper, lot and plating specification | The current path and the clinch material are as specified |
| Cross-section | Polished and etched cut through the axis | The bond is continuous and the clinch is sound |
| Strength test | Shear on the bond, pull on the assembly, with failure mode | The joint carries the intended load |
| Resistance test | Four-wire reading at a stated current and probe position | The finished assembly meets its electrical limit |
| Plating record | Thickness, coverage and any barrier layer | The contact face and the carrier interface are protected |
Add the carrier drawing and the staking specification where the contact is supplied as an assembly.
Electrical and functional evidence
Contact resistance should be measured on the finished assembly at a stated current, with stated probe positions. A four-wire reading from the face to a point on the carrier includes the bond and the clinch, which is what the application sees. Report the current, the force and the temperature.
Force and travel belong in the pack where the contact is a spring. A load at a stated deflection is more useful than a free height alone. If the part is a rivet, the staked height and foot diameter are the functional dimensions.
A life test is usually a type test, not a first article item. Keep the distinction clear, or the pack becomes a qualification report and the lot release gets delayed.
Review, sign-off and retention
The pack should carry a clear statement of what was measured, what was not, and any deviation. A concession is not a failure of the pack, provided it is written down and accepted by the drawing owner. An unrecorded deviation is the problem.
Sign-off needs a name, a date and a revision. Store the pack with the first production lot and keep the retained samples. When a later change appears, the first article is the baseline that shows what changed.
Finally, define what triggers a new FAI. A new tool, a new material batch, a change of plating line, a moved process or a drawing revision should all start a fresh check. The pack is a record of a process at a point in time, not a permanent certificate.
Frequently asked questions
How is a contact FAI different from a material certificate?
A material certificate describes the material lot. A first article report describes the finished part and links the dimensions, the joint, the electrical result and the material records to one build. The certificate is one input to the pack, not the pack itself.
Does a mill certificate prove the part material?
Only if the certificate lot can be traced to the material used for the part. Check the lot on the certificate, the material label and the production record. A correct chemistry on an unrelated lot proves nothing about the parts in the box.
How many parts should a contact FAI cover?
The standard or the customer requirement sets the number. As a practical minimum, cover parts from each cavity or head position and include enough samples for the destructive checks. The first article is a process check, so it should represent the production condition.
What triggers a new FAI?
A drawing revision, a new tool, a new material batch or supplier, a change of plating or heat treatment line, a moved process or a significant corrective action. The trigger should be written into the supplier agreement, not decided case by case.
Sources and further reading
- AS9102, Aerospace first article inspection requirement
- AIAG Production Part Approval Process (PPAP), 4th edition
- Qumek contact FAI and material traceability notes
Qumek Engineering Desk
Engineering team
The engineering team behind Qumek drawings, DFM notes, tolerances and inspection standards. Every guide is reviewed against the drawings and processes used on live programmes.
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Send the drawing revision, the material callouts and the joint specification. The engineering desk will reply with a written checklist for the pack.
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