# Certificates of Conformance and Material Traceability for Aerospace Parts > Source: https://netray.co/resources/aerospace-certificate-of-conformance-material-traceability > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Knowledge Base ## Short answer What goes in an aerospace certificate of conformance, how to trace heat and lot numbers from mill cert to shipped part, and keep records auditors accept. ## Category erp-general ## Content **Intro:** An aerospace certificate of conformance states that the parts shipped meet the PO and drawing requirements, and it must be backed by traceability: a record linking the finished lot to the raw material heat or lot, the mill test report, each special process certificate and the inspection results. AS9100D clause 8.5.2 requires identification and traceability where specified, and primes commonly require it. Build the chain at receiving, keep it attached to the job, and generate the C of C from verified data. This guide shows the chain, the usual gaps, and where software and AI can reduce errors. **Sections:** #### The Traceability Chain From Mill Cert to Shipment **Body:** Start at receiving: record the supplier, spec, heat or lot number, quantity and condition from the mill test report, and verify it against the PO and spec, for example AMS 4027 aluminum plate or AMS 5643 stainless bar. Tag or log the bar or plate with an internal lot ID. When material is cut and issued to a job, record the lot against the job number, and where parts are serialized or lot-controlled, carry that identity through each operation. Outside processing returns with its own certificate referencing your lot. At final inspection, the C of C links part number, revision, quantity, job, material lot and process certs. Break the chain anywhere, for example by remnants without tags, and you cannot ship traceable product. #### What a C of C Should Contain **Body:** Content varies by customer and PO, so read the quality clauses, but the common elements are consistent. **Bullets:** - Your company name, address and quality approval or cage code as required - Customer PO number, part number and drawing revision, quantity shipped - Material specification with heat or lot number and the traceable mill cert reference - Special processes performed with specification, revision and processor name - Statement of conformance to drawing, specification and PO, with any approved deviations or concessions - Authorized signature, title and date #### Typical Gaps Auditors and Customers Find **Body:** Common findings: mill certs filed by PO not by lot, so tracing from a part back to the cert requires digging; remnants and drops of bar stock returned to the rack without markings; special process certs received but not matched to the specification revision on the drawing; C of Cs typed by hand with transcription errors; and counterfeit or suspect material controls absent. Also watch material origin. Defense work may require domestic specialty metals under DFARS 252.225-7009, so country of melt must be on the cert. Keep a documented procedure for suspect material and for quarantine of nonconforming stock, as AS9100D 8.1.4 requires counterfeit part prevention. #### ERP Practices That Make It Work **Body:** Use lot-controlled inventory items for raw material, require a lot number at receipt, and issue by lot to jobs so the system holds the link. Attach scanned certs to the receipt record, not to a folder by date. Generate the C of C from the job record so material lot, process vendors and quantities come from data rather than retyping, and have quality review and sign. Shops on JobBOSS, E2, Global Shop, ProShop, Epicor or SyteLine can all do this if configured; the failure is usually not using the lot features consistently. Retention periods may be long, so confirm archive and backup of the cert images and records. #### AI for Cert Checking, With a Human Sign-Off **Body:** Mill certs and process certs arrive as PDFs and scans in varied formats. A private AI model can extract heat number, chemistry, mechanicals and specification, compare them to the required spec limits, and flag mismatches or missing fields, such as a missing country of melt. Results go to a receiving inspector to confirm. It does not replace inspection, and it should not write to inventory without approval. If you receive only a handful of certs a week, manual checking against a template is fine. **Cta:** Show Netray a sample mill cert and process certificate set, and see how a private model extracts and checks them against your PO before a person approves. **Faq:** #### What is the difference between a certificate of conformance and a mill test report? **Answer:** A mill test report comes from the material producer and documents chemistry and mechanical properties for a heat or lot. A certificate of conformance comes from the supplier of the finished product and states that the shipment meets the order requirements. Your C of C should reference the mill report and process certs. #### How long do I need to keep traceability records? **Answer:** It depends on the customer and contract. Many aerospace and defense purchase orders require retention for ten years or more, and some require longer or require notification before destruction. Check the retention clause on each PO and set your policy to the longest you accept. #### Do I need serial numbers or are lot numbers enough? **Answer:** Follow the drawing and PO. Many machined parts need lot traceability only, while flight-critical or life-limited parts require serialization. If the PO is silent, confirm with the customer rather than assuming. #### Can I print C of Cs from my ERP? **Answer:** Most shop ERPs can generate one from the job and shipping records, provided material lots and process vendors are captured as data. Have quality review each certificate before it ships. ## Related Slugs - lot-traceability-electronics-manufacturing - how-to-set-up-syteline-as9100-compliance - syteline-receiving-inspection-setup - supplier-risk-management-manufacturing ## Search terms certificate of conformance aerospace, C of C requirements machine shop, material traceability mill cert heat number, AS9100 identification and traceability, aerospace record retention requirements, lot traceability machine shop ERP --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json