What Material Documents Should Buyers Request for LM6 or A413 Castings?
Buyers should request the controlling material standard and revision, purchase callout, alloy designation, certificate of conformity, traceable heat or melt chemistry, part-to-lot record, approved substitution or deviation, first-article evidence and change-notification requirements. For critical applications, add source-controlled property or functional records appropriate to the drawing. No single certificate proves all of these items.
The document package should answer four questions: What requirement applied? What material was actually melted? Which delivered parts came from that material and process? Who approved any difference between LM6 and A413? If one answer depends on an email or verbal statement, the repeat-order baseline is incomplete.
Separate Standard, Grade and Conformity Documents
The drawing or purchase specification is the requirement source. It should identify LM6 under the applicable BS 1490 reference, A413 under the applicable purchase framework, or an approved custom envelope. Record revision. A supplier datasheet can describe a nominal product but does not replace the governing standard.
A certificate of conformity is the supplier's statement that delivered parts meet the order. It should identify supplier, customer order, part number and revision, quantity, material callout, lot and authorized signatory. It may not contain measured chemistry, so read its fields instead of treating the phrase “CoC supplied” as complete material evidence.
A heat, melt or spectrometer report provides actual composition for an identified sample. Require all elements controlled by the approved specification and a link to the delivered casting lot. If results are transcribed from another system, retain the original source identity and prevent manual mixing of melts.
Link Material Evidence to Delivered Parts
Document | Issuer | What It Proves | Retention or Review Point |
|---|---|---|---|
Controlled drawing/material specification | Design or configuration authority | Required grade, standard, condition and acceptance | Keep revision effective for each order |
Certificate of conformity | Supplying organization | Supplier's declaration against the purchase order | Check lot, part, quantity and callout |
Measured chemistry report | Melt source or qualified laboratory | Element values for the identified heat/melt sample | Verify method, complete elements and part linkage |
Lot traveler or trace record | Manufacturer | Connection among melt, tool/cavity, machining, finish and shipment | Retain through the required product-life period |
Deviation or equivalence approval | Authorized buyer/design owner | Permission and conditions for A413 against LM6 | Check source, quantity, revision and expiration |
First-article/validation report | Manufacturer and approving customer functions | Selected dimensions and tests on identified samples | Does not replace ongoing lot controls |
Change notification | Supplier | Proposed source, material or process change before shipment | Route through reapproval before implementation |
Traceability can be lot-level or individual depending on risk and contract. At minimum, the buyer should be able to take a shipped package and identify its casting lot and supporting chemistry. If machining or coating can materially affect function, the same traveler should identify those batches. Packaging labels must not be the only record because they can be separated from parts.
Receiving inspection should compare fields, not only file presence. Check that part number, revision, purchase order, quantity, alloy, standard, heat or melt and shipment lot agree across the certificate, chemistry report and label. A valid chemistry report attached to the wrong lot is not evidence for the shipment. Mismatched units, transposed element columns or copied revision numbers deserve a documented hold and clarification.
Digital records need version and access control. Preserve the original signed or issued report, then link any extracted values to it. If a supplier corrects a certificate, retain the superseded copy and correction reason. Silent replacement destroys the audit trail and can hide whether parts were released against incomplete information.
The aluminum alloy library is a reference source, not a delivered-lot certificate. Similarly, a testing page describes equipment categories but does not prove that the particular LM6 or A413 shipment was analyzed. Use actual reports.
Retain the Substitution Basis Through Repeat Orders
Consider a hypothetical annual order sourced from two foundries. One supplies LM6; the other supplies approved A413. The buyer keeps separate approved-source records, standard matrices and chemistry targets. The A413 deviation identifies its source and process. Receiving can therefore verify the correct certificate package instead of accepting either label under one generic item.
Define retention based on contractual, regulatory and product-life needs. The supplier and buyer should agree who keeps original chemistry, first article, deviation, inspection and change records and how quickly they can be retrieved. A spreadsheet summary is useful but should not overwrite source reports or revisions.
Use repeat-production controls to monitor standard revisions, sources and process changes. New melt supplier, altered chemistry target, different casting route, major tool repair, heat treatment, machining fixture or finish may require notification even if the alloy name remains unchanged.
The final release packet should be short enough to audit and complete enough to reconstruct the decision. Requirement, actual material, represented parts and approval authority must align. That discipline protects the buyer from both false equivalence and paperwork that looks complete while proving very little.
