Link documents to the actual object
A raw-material document need not cover a molded, colored or post-treated part. Map grade to production lot and finished part/revision, and define whether each document supports material properties, batch testing or contractual conformity. Suppliers may use abbreviations differently; the document's content governs.
Separate typical values from acceptance limits
Typical properties aid material understanding and do not automatically become every-lot release requirements. Specify limits, methods, specimen conditions and sampling for accepted characteristics. If a COA reports only pass, confirm whether the contract permits this and whether underlying records are traceable.
Close the incoming-document chain
Align package labels, delivery notes, report lots and purchasing revisions. Record missing evidence and its release implications for the agreed decision-maker; a new stamp is not a repeated test. This checklist does not claim Chengxin holds a particular certification or report-issuing qualification.
Project review checklist
| Document | Review focus | Boundary |
|---|---|---|
| TDS | Grade, revision and test conditions | Typical values are not automatically acceptance limits |
| COA | Lot, characteristics, results and methods | Only the tests actually listed |
| COC | Scope, requirements and issuer | Not proof of measured data for every item on every lot |
Illustrative project example
An order requiring finished dimensions and sealing tests cannot be closed with only a raw-material hardness TDS. It helps identify the compound but does not establish finished-part conformity.
Frequently asked questions
Is a COA still needed when a COC is supplied?
Purchasing requirements and risk decide. A declaration generally cannot replace batch measurements explicitly required by contract.
Can an unnumbered report release a batch?
It may be general reference information; batch release needs adequate linkage and agreed approval.
Related product and project inquiry
Custom Shaped Silicone Parts · Silicone Shipment Documents: Matching Batches, Reports and Samples
For a custom part review, send the drawing, application, material or performance needs, key dimensions, quantity and target test conditions. Material, tooling and acceptance requirements are confirmed for each project.
