Part Marking, IUID and Labels for Defense and Aerospace Hardware

Updated October 12, 2026

Marking types and where each is used

Choose the method by the substrate, the environment and whether the part can tolerate it. A fatigue critical forging, a coated housing and a wire harness need three different answers.

Harness and wire identification is often printed on heat shrink sleeves, covered on the heat shrink and sleeving page.

The rules that govern marking and IUID

Since 2008 the clause has not named a MIL-STD-130 revision; DoD changed it to require the version cited in the contract schedule. Read the schedule before you set up the marking.

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When an item needs a UII under DFARS 252.211-7003

Paragraph (c)(1) of the January 2023 clause lists five cases:

1. Delivered items with a Government unit acquisition cost of $5,000 or more, except line items the contract excludes.
2. Items under $5,000 that the schedule or a table in the clause identifies.
3. Subassemblies, components and parts embedded in delivered items, items with warranty requirements, and DoD serially managed reparables and nonreparables, as an attachment specifies.
4. Special tooling and special test equipment designated for preservation and storage for a Major Defense Acquisition Program.
5. Any other item the contractor chooses to mark with a unique identifier for traceability.

The clause also forbids reusing an identifier on any other item marked or registered. Delivered end items are reported to the IUID Registry through the WAWF receiving report, and embedded items through WAWF, direct submission to the Registry or an attachment. The defense contractors page covers how this clause sits with the other DFARS flow downs.

How a UII is built

A UII is a string of data elements encoded in a Data Matrix. The clause defines two concatenated constructs, and the issuing agency code is derived from the data qualifier rather than marked on the item.

Published summaries of MIL-STD-130 report that most companies use Construct 2, which suits serial numbers that restart for each part number. Construct 2 carries the original part, lot or batch number, so choosing the construct is a configuration decision for engineering, not a label shop decision. The clause requires the marks to be verified as machine readable with an automatic identification device programmed to MIL-STD-130 Appendix A, and MIL-STD-130 practice calls for a verified grade of B or better.

Marking that does not harm the part

The drawing decides where and how a part may be marked, and a supplier should never improvise. Part standards are explicit about it: AS21919, for example, says to mark the clamp part number and manufacturer per AS478 method 2A1 and not to mark in the radius. Apply the same discipline to your own parts.

• Stress and fatigue. Dot peen and deep laser marks are surface stress raisers. Keep them off fillets, radii, holes and highly stressed surfaces, and get the stress engineer to approve any direct mark on a fatigue critical part.
• Coatings. Marking through anodize, chem film or paint breaks the protection. Either mark before finishing with a method the finish will not erase, or use a label or plate. The surface finishing page covers the finishes involved.
• Material. Chemical etch and some inks can attack certain alloys or composites; require the marking process to be approved for the material.
• Function. Keep marks off sealing faces, bearing bores, mating surfaces and anything inspected for surface finish.

Human readable text alongside the Data Matrix should be sans serif, and MIL-STD-130 recommends a minimum character height of about 0.08 in (0.2 cm).

Label materials and adhesives for the environment

MIL-STD-130 expects the mark to be as permanent as the normal life of the item, so a label is only acceptable if it lasts that long in service. Set the requirement by environment, then let the label supplier show test data.

• Facestock. Polyester is the general purpose choice. Polyimide is used where labels see higher temperatures, such as near electronics during reflow or on hot equipment. Metal foil and photo processed aluminum plates are used outdoors and on GSE.
• Adhesive. Acrylic adhesives are common on durable labels, but the substrate decides the grade. Low surface energy plastics, powder coat and textured paint need adhesives rated for them.
• Surface prep. Most label failures are surface failures. Specify cleaning before application and a dwell time before the part is handled or cleaned.
• Exposure. List the fluids (hydraulic fluid, fuel, cleaning solvents), temperature range, UV and abrasion the label must survive, and require the data matrix to still verify after exposure.
• Space and cleanroom. Labels are polymers and adhesives, so they fall under outgassing screening like other nonmetals; see engineering plastics for the ASTM E595 screen.

What to put on the purchase order

• Marking requirement and revision: MIL-STD-130 at the revision the prime contract cites, and DFARS 252.211-7003 if it is flowed down.
• Which items need a UII, the construct to use, and the enterprise identifier (CAGE) that goes in the mark.
• Marking method and location per drawing, and any prohibited areas.
• For labels and plates: facestock, adhesive, attachment method and the environmental requirement.
• Verification report showing the Data Matrix grade for each marked item or a sample per your plan.
• Who reports to the IUID Registry, and what data the supplier must hand back for that report.
• Shipment and container labels to MIL-STD-129 when the contract requires it.

Counterfeit and quality risks, and how to receive marked items

A mark is an identity claim, so it is a target. Counterfeit electronic parts are often remarked, and a relabeled assembly can carry a UII that belongs to another item. At receiving:

• Scan every Data Matrix and compare the decoded UII and part number to the packing list and certificate.
• Check for duplicate UIIs across the lot; the clause forbids reuse.
• Look for signs of remarking: sanded or blacktopped surfaces, labels over old labels, inconsistent fonts.
• Confirm the human readable text matches the encoded data.

See counterfeit parts avoidance for source controls and material certs and traceability for how marks tie back to records.

How we source marking, labels and marked parts

We do not hold label stock or publish prices. We flow your MIL-STD-130 and IUID requirements down to the shops making your parts so items arrive marked, verified and documented, and we buy labels, nameplates, placards and decals to your drawing through qualified suppliers with traceability. Marked parts, plates and the hardware that attaches them can all sit on one PO, and we can kit them with the assemblies they go on. For hard to find legacy plates or labels we work under our obsolete parts controls. Related: cushion clamps, caps and plugs, and all protection parts.

Get marked parts quoted

Send the drawings or a parts list with the marking note, the contract clauses that flow down and the label environment. Request a hardware quote; a person replies within one business day. Controlled drawings follow the controlled programs process.

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Send the job. A person replies within 1 business day.

Part, quantity and date are enough to start. Drawings and the mutual NDA follow by reply, and controlled programs never send technical data through this site.

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Service *CNC machiningSheet metal, welding and fabricationAdditive manufacturing (metal and polymer)Composites fabrication and repairWire harness and cable assemblyElectronics and PCB assemblyGround support equipment, lifting and handlingTooling, jigs and fixturesTubing, fluid lines and pressure systemsObsolete and hard-to-find parts (AS6081 sourcing)Certified surplus material (titanium, Inconel, aluminum)Certified fasteners, hardware and raw materialTest lab time (vibration, thermal vacuum, cleanroom)Precision cleaning and oxygen serviceFinishing and special processes (anodize, plating, heat treat)Inspection, NDT, CMM and first articleCertified small-business subcontractorsEngineering, drafting and DFMCrating, transport and chain-of-custody logisticsContract technicians and skilled laborSomething else

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Questions

Related

• Heat Shrink Tubing and Sleeving for Aerospace Harnesses
• Cushion Loop Clamps for Wire Bundles and Tubing
• Protective Caps, Plugs and Covers for Aerospace Hardware

Sources

• Acquisition.gov: DFARS 252.211-7003 Item Unique Identification and Valuation (JAN 2023)
• Acquisition.gov: DFARS subpart 211.2 (252.211-7008 prescription)
• Federal Register 2008 final rule on DFARS 252.211-7003 and MIL-STD-130
• Wikipedia: MIL-STD-130 (revision history, marking methods, constructs)
• UMPCO: AS21919 drawing notes, marking per AS478 and no marking in radius (PDF)
• ASTM E595 outgassing test method