Metals Chain of Custody: Documentation Requirements and Best Practices

Quick Answer

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In metals supply chains, a chain of custody is not just a phrase from law enforcement. It is a formal documentation trail that industrial customers, inspection bodies, and regulatory authorities use to verify that the material in a finished structure or system is genuinely what the certificate says it is.

This guide explains what goes into a metals chain of custody, how documentation must flow through each stage of the supply chain, and where the most common breaks occur.

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What Is a Metals Chain of Custody?

A chain of custody in metals documents every transfer of ownership or physical control of a material, from the point of production to its final installation. At each link in the chain, the following must be recorded:

• Who received or transferred the material
• When the transfer occurred
• What material was transferred — grade, dimension, quantity, and heat number
• What documents accompanied the transfer — MTC, delivery note, packing list
• What verification was performed — was the heat number on the material checked against the certificate?

The chain is only as strong as its weakest link. A single undocumented transfer — or a transfer where documents were not verified — creates a gap that can unravel the entire traceability case.

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The Links in a Metals Supply Chain

Mill (Steelmaker or Foundry)

The chain begins at the producer. The mill assigns the heat number, conducts the required tests (chemistry, tensile, impact, dimensional), and issues the mill test certificate. The MTC is the originating document for all subsequent chain of custody records.

Stockholder or Distributor

Most metals do not flow directly from mill to fabricator. A stockholder (service center or distribution center) takes delivery from multiple mills, cuts and processes material for resale, and re-issues documents.

At this stage the distributor's responsibilities include:

• Retaining the original MTCs received from each mill
• Re-marking cut material with the original heat number before resale
• Issuing their own delivery note and certificate (or certified copy of the original MTC) that clearly references the mill's heat number
• Not mixing heats in a single delivery without clearly separating the documentation

Fabricator or Processor

The fabricator receives material and documents it at receiving. Responsibilities include:

• Logging the receipt with heat number, quantity, and certificate reference
• Performing a receiving inspection to verify the physical material against the certificate
• Registering the material in their material control system
• Issuing an internal tag or works number that links to the heat

During fabrication, every operation that consumes or transforms material must reference the heat number: cut records, weld records, heat treatment records, inspection records.

Site or End User

At installation, the material may need to be verified against its traceability record — particularly for pressure equipment, structural connections, and safety-critical applications. The end user or contractor typically assembles the traceability records into a data book or turnover package that is submitted to the owner, operator, or regulatory body.

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What Documents Form the Chain

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EN 10204 Certificate Types and Chain of Custody

EN 10204 is the European standard that defines inspection document types. Understanding which type is required affects how chain of custody obligations are met:

• Type 2.1 / 2.2 — A declaration of compliance or internal test report. Issued by the producer. Lowest traceability level; common for commodity products.
• Type 3.1 — Inspection certificate issued by the producer's authorized representative, based on specific tests on the delivered material. This is the most common type for pressure equipment materials.
• Type 3.2 — Test certificate validated by an independent third party (typically the purchaser's inspector or a notified body). Highest traceability level; required for safety-critical applications.

When material is processed and re-sold by a distributor, they may issue a new 3.1 certificate under their own authorization — but it must reference the original mill heat number. A distributor cannot issue a new certificate that erases the connection to the original mill data.

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Where Chains of Custody Break

The "No Certificate" Delivery

Material arrives without an MTC. The delivery driver says "the paperwork will follow." It often does not. The material goes into stock and the certificate never arrives. Months later, the material is issued to a job and there is no certificate to trace it to.

Prevention: Implement a no-certificate-no-acceptance policy at the goods receiving dock. Hold the material in quarantine until the document arrives and is matched.

Re-Marking Failures After Cutting

A distributor cuts a plate into smaller pieces and ships them to different customers. One customer receives a piece that was not re-marked with the original heat number. The piece goes into their stock with only the distributor's delivery number as an identifier.

Prevention: Require re-marking certification in your purchase order terms. Inspect incoming cut material for visible heat number marking.

Certificate Pooling

A supplier has several heats of A36 plate in stock that all pass the same specification. They issue a single MTC for a mixed-heat delivery, or apply one certificate to material from a different heat. This is a form of document fraud, but it also occurs accidentally when certificates are managed carelessly.

Prevention: Verify that the heat number on the physical material matches the heat number on the certificate at receiving, piece by piece.

Internal Transfer Gaps

Within a fabrication shop, material is moved from one bay to another or issued from stores to the production floor without a formal record. The physical tag falls off. The link between the material and its certificate is broken.

Prevention: Require a signed issue slip for every material movement. Treat internal transfers the same way you treat supplier deliveries.

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Building a Robust Chain of Custody System

Effective chain of custody management is less about sophisticated technology and more about disciplined process at each transfer point. The core requirements are:

1. Document retention — every MTC, delivery note, and receiving record is stored and retrievable by heat number
2. Physical marking — material carries a visible, durable identifier at all times
3. Verification at receipt — someone physically compares the marking on the material to the certificate before the material is accepted
4. Issue control — no material leaves stores without a record that identifies the destination and heat number
5. Remnant management — cut pieces are re-marked before returning to stock

Digital tools like TestCert enable systematic chain of custody management by linking each MTC to POs, receiving records, and cut/issue transactions — making the documentary chain retrievable in seconds rather than hours.

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Frequently Asked Questions