Twelve clauses a clad quality agreement needs
Most disputes about clad material are not about quality. They are about two parties holding different documents. These are the twelve clauses that close the gap.
At a glance
Specification at a glance
| Clause | What it fixes | Typical wording |
|---|---|---|
| 1. Structure | The layer split and grades | 3-ply SUS304 / AL1050 / SUS430 as per drawing X rev Y |
| 2. Gauge | Total and per-layer thickness with tolerance | Total 2.50 mm, plus or minus 0.10 mm |
| 3. Dimensions | Diameter or width, tolerance, edge | Diameter 300 mm, plus or minus 0.5 mm, deburred |
| 4. Flatness | Limit, method and timing | 0.5 mm over the disc, measured 24 h after cutting |
| 5. Surface | Finish name, Ra range, inspection light | Satin, Ra 0.4 to 0.8, inspected at 500 lux |
| 6. Bond integrity | Test method and acceptance | No separation after the agreed bend or shear test |
| 7. Documents | What ships with each lot | Mill certificate, inspection record, packing list |
| 8. Sampling | How many pieces per lot are checked | Per AQL level stated in the annex |
| 9. Retained samples | What is kept and for how long | One piece per lot, retained 24 months |
| 10. Non-conformance | What happens on a failure | Notification within 3 days, credit, replacement or sort |
| 11. Change control | Any change to material or process | Written notice 30 days before shipment |
| 12. Marking | Lot identification on the bundle | Batch reference, gauge, grade, quantity |
Why twelve and not two
Buyers usually write two: structure and price. The disputes then come from the ten that were never written: which flatness, measured when, on how many pieces, with which light. Each of those has a defensible answer and a wrong one, and only the written one settles the argument.
Numbers instead of adjectives
"Good surface" cannot be inspected. "Satin, Ra 0.4 to 0.8, at 500 lux, at 500 mm" can. The same applies to flatness and to bond integrity: a limit without a method is a preference.
Change control protects both sides
A silent change of annealing condition or a different aluminium source can change how the material draws. Thirty days' notice of a material or process change is not bureaucracy; it is what lets a press shop requalify before a shipment lands.
Retained samples end most arguments
A piece per lot, kept for two years, settles a claim raised months later. It costs almost nothing and it is the single most useful clause in the list.
How to start
Send your current purchase specification. The reply marks which of the twelve are already covered, which are ambiguous, and which are missing. That comparison is quicker than drafting a new agreement from scratch.
Questions
Common questions
Is a quality agreement necessary for small orders?
Yes, and it is shortest for small orders: structure, gauge, dimension, documents. The disputes that hurt are usually about a dimension nobody wrote down.
Who should hold the retained samples?
Whoever can produce them when a claim is raised. In practice the supplier keeps them and the buyer may keep a matching set.
What is a reasonable flatness limit?
It depends on the part and the gauge. The number matters less than stating the method and the timing with it.
Can the agreement reference your standard instead of ours?
It can reference either, provided the standard is attached and unambiguous. A reference to an unseen standard is not an agreement.
How is bond integrity tested?
By an agreed mechanical test such as a bend or shear, with the acceptance criterion written. Ultrasonic inspection is a different, more expensive conversation.