AS6171 Explained: What the Counterfeit Testing Standard Requires

Key Takeaways

• SAE ownership: AS6171 is published and maintained by SAE International, the same body responsible for a wide range of aerospace and automotive engineering standards.
• Six core test methods: visual inspection, X-ray inspection, XRF analysis, curve trace electrical testing, heated solvent testing, and decapsulation die analysis form the primary toolkit accredited UK labs use to detect counterfeit parts.
• ANAB accreditation under ISO/IEC 17025:2017: a lab’s AS6171 results only carry third-party legal weight if ANAB has accredited that specific lab’s scope for that specific test method.
• Cost versus risk: AS6171 testing typically runs £50 to £500 per component, against field failure costs that can run into hundreds of thousands or millions of pounds.
• Turnaround expectations: most accredited labs quote 5 to 15 working days depending on which test methods are required and current backlog.

What is AS6171?

AS6171 is the SAE standard covering counterfeit electronic component detection. It was written to give aerospace and defence procurement teams a defensible, repeatable way to test parts sourced outside authorised distribution channels, particularly from the secondary market, brokers, or reclaimed stock. The standard doesn’t rely on a single test. Instead it defines a structured set of visual, electrical, and destructive methods that, used together or selectively depending on risk, build a picture of whether a component is genuine, has been re-marked, or has been through unauthorised rework.

The standard was born out of a real problem. Aerospace and defence supply chains rely heavily on long-lifecycle components, many of which go obsolete long before the platforms they support are retired. That gap between component availability and platform service life pushes buyers towards secondary market sourcing, where counterfeit risk is highest. AS6171 gave the industry a common language and a common test regime rather than each prime contractor inventing its own.

That origin in aerospace and defence hasn’t limited where the standard is now used. Automotive electronics, industrial control systems, and medical device manufacturing have all adopted AS6171 testing as part of their own component qualification processes, largely for the same reason: high consequence of failure, long product lifecycles, and growing exposure to secondary market sourcing as parts age out of production. A counterfeit sensor in a car’s braking system carries the same real-world risk profile as a counterfeit part in an aircraft, even though the contractual obligations differ.

SAE maintains and updates AS6171 as a formal specification, publishing the current scope and test method definitions directly. This matters because the standard isn’t static. Test methods get refined as counterfeiting techniques evolve, so a lab’s accreditation scope should reflect the current published version, not an outdated one. When you’re evaluating a UK testing partner as part of your quality control strategy, checking which version of AS6171 they’re accredited against is a legitimate first question, not a technicality.

Which Six Test Methods Does AS6171 Define?

AS6171 defines several test methods, but six form the backbone of what accredited UK labs actually offer. Each targets a different failure mode a counterfeiter might try to hide, and none of them substitutes for the others. A component that passes visual inspection can still fail decapsulation. A component with correct elemental composition can still have the wrong die inside. That’s why testing programmes combine methods rather than relying on one.

1. Visual inspection testing comes first in almost every workflow. It examines surface condition, printed markings, solder joint quality, and packaging integrity under magnification. Re-marked parts often show inconsistencies here: font mismatches, laser marking depth that doesn’t match the manufacturer’s known process, or sanding marks where original markings were removed.
2. X-ray inspection testing looks inside the package without opening it. It maps internal layers, die attachment, and wire bonding, and flags voiding that shouldn’t be present in a genuine part. This is often the first method to catch a part that’s been repackaged with a different die inside the same outer casing.
3. XRF analysis testing checks elemental composition of leads, solder, and plating. Genuine manufacturers use consistent material formulations. Counterfeiters reworking or re-plating leads frequently introduce elemental signatures that don’t match the OEM’s known specification, and XRF picks that up quickly without damaging the part.
4. Curve trace electrical testing moves from physical inspection to functional verification. It analyses the device’s parametric electrical signature and compares it against the known-good profile for that part number. A part that looks correct externally but fails to match its expected electrical curve is a strong counterfeit indicator.
5. Heated solvent testing removes solder to inspect underlying material for signs of prior rework, re-marking, or substrate substitution. It’s a more invasive step, typically reserved for parts that raise concerns under the earlier, non-destructive methods.
6. Decapsulation die analysis is the most conclusive and most destructive method. It opens the package to expose the silicon die directly, allowing inspection of die size, internal markings, and manufacturing process node. This confirms, beyond doubt, whether the silicon inside matches what the part number claims to be.

Other destructive methods exist within the broader AS6171 specification, but these six represent the primary methods offered by accredited UK labs, and together they cover the range from quick screening to definitive confirmation.

Why Does AS6171 Matter for Supply Chain Integrity?

A counterfeit component that passes undetected doesn’t just cost money when it fails. It fails at the worst possible moment, in the field, often in a system where failure means something far more serious than a warranty claim. Aerospace, defence, and medical electronics sit at the sharp end of this risk, and that’s exactly why AS6171 exists.

Original equipment manufacturers in these sectors are frequently under contractual obligation to test components sourced from anywhere outside the original manufacturer’s direct channel. Secondary market stock, broker-sourced parts, and obsolete components pulled from long-tail inventory all fall into this category. Skipping the test isn’t an option when the contract specifies it, and increasingly, it doesn’t specify a vague “inspection.” It names AS6171 directly.

There’s a legal dimension here too. When a component fails and the resulting investigation asks “did you test this before installation,” an AS6171 test report from an accredited lab is a real answer. Internal visual checks or an engineer’s judgement call are not. The accreditation is what turns a test result into something defensible in an audit, an insurance claim, or a regulatory review.

Regulatory bodies have caught up with this reality. The FAA and EASA increasingly expect evidence of formal counterfeit testing for critical components entering aerospace supply chains, and that expectation is starting to filter into automotive and industrial sectors handling safety-critical electronics too. A component buyer who can produce AS6171 documentation on request is in a fundamentally stronger position than one who can’t, whether that request comes from a regulator, an insurer, or a customer’s own quality team.

This connects directly to obsolescence management. Components at end-of-life are exactly where the secondary market becomes unavoidable, and exactly where counterfeit risk climbs. A buyer sourcing obsolete stock to keep a legacy product line running has no direct manufacturer relationship to fall back on for authenticity assurance. AS6171 testing fills that gap. It’s the mechanism that makes buying obsolete or hard-to-find stock a calculated risk rather than a gamble.

How Do You Know If a Lab Is Truly AS6171 Accredited?

Not every lab that offers AS6171 testing is actually accredited to perform it. This distinction matters more than most buyers realise, and it’s worth understanding before you send components anywhere.

Genuine AS6171 accreditation is granted by ANAB, the ANSI National Accreditation Board, under the ISO/IEC 17025:2017 framework for testing and calibration laboratories. This isn’t a badge a lab can print for itself. It requires third-party assessment of the lab’s methods, equipment, staff competency, and quality management system, renewed on a defined cycle. A lab holding this accreditation has been independently checked. One that doesn’t hasn’t.

Here’s the part buyers often miss: a lab can run AS6171 test methods perfectly competently without holding accreditation for them. Nothing stops a lab buying an X-ray machine and offering “AS6171 inspection.” What that lab can’t offer is third-party assurance that the result will stand up to scrutiny. If a regulator, auditor, or insurer later asks who verified the lab’s competence to run that test, the answer is nobody. The test happened. The assurance didn’t.

Before submitting components anywhere, ask for the lab’s ANAB certificate number, its expiry date, and, critically, its scope document. The scope lists exactly which of the six AS6171 test methods that specific lab is accredited to perform. A lab can hold accreditation for visual inspection and X-ray while having no accredited scope for decapsulation or curve trace, for example. Assuming full coverage without checking the scope is a common and avoidable mistake.

In the UK, Retronix, Princeps, and SMT Corp’s UK lab all currently hold valid ANAB accreditation for AS6171 test methods through 2026. That’s a useful starting reference point, but accreditation scope and expiry dates change, so verify current status directly with any lab before committing a project to them.

For a fuller comparison of UK providers and how their accreditation scopes and standards stack up, see our guide to counterfeit component testing providers in the UK.

How Should You Integrate AS6171 Into Your QC Workflow?

AS6171 testing isn’t something you bolt onto every incoming shipment regardless of source. Applied that way, it becomes a cost centre with no strategic logic behind it. Applied with a defined trigger point, it becomes a genuine risk control.

The clearest triggers are high-value components, parts destined for critical applications in aerospace, defence, or medical devices, anything sourced from the secondary market or reclaimed stock, and components from suppliers where the chain of custody has a gap. If a part came through a broker rather than an authorised distributor, that’s a gap worth closing with testing.

You don’t need to test 100% of every lot to build a defensible programme. A risk-based sampling plan, applied consistently and documented clearly, holds up far better under audit than an inconsistent policy of testing everything from one supplier and nothing from another. The plan itself, and the reasoning behind it, is part of what makes the programme defensible.

Turnaround varies by test method and lab backlog, but most accredited UK labs quote between 5 and 15 working days. Build that into procurement timelines for critical projects rather than discovering it during a deadline crunch.

Cost versus risk is where this becomes a straightforward decision on paper, even if it doesn’t always feel that way against a tight budget. AS6171 testing typically runs from £50 to £500 per component depending on the methods used. A field failure in a critical application can cost anywhere from £10,000 to over £1,000,000 once you account for investigation, replacement, downtime, and reputational damage. That comparison rarely favours skipping the test.

Finally, keep the paperwork. Test reports, certificates of analysis, and full traceability records need to be retained, not just generated. When an auditor or customer asks for evidence six months or two years later, the report needs to be retrievable, complete, and tied clearly to the specific lot or serial numbers it covers. A testing programme without retained documentation offers no more protection in an audit than not testing at all.

Frequently Asked Questions

Does Systemation Euro hold AS6171 accreditation?

Systemation Euro is working towards additional third-party accreditations as part of our ongoing quality development programme. For AS6171 counterfeit testing specifically, we recommend engaging one of the ANAB-accredited UK labs named in this guide, and our team can help you scope which test methods your components need before you submit them.

Is AS6171 testing mandatory for every component I buy?

No. AS6171 is typically required contractually for aerospace, defence, and medical components sourced outside authorised distribution channels, or for high-value and safety-critical parts pulled from secondary market or obsolete stock. A risk-based sampling approach, rather than blanket testing of every incoming lot, is generally considered defensible under audit.

How much does AS6171 testing cost per component?

Costs typically range from £50 to £500 per component depending on which of the six test methods are required. Non-destructive methods like visual inspection and X-ray sit at the lower end, while destructive methods such as decapsulation cost more due to the specialist equipment and irreversible nature of the test.

How long does AS6171 testing take?

Most ANAB-accredited UK labs quote turnaround times of 5 to 15 working days, depending on which test methods are needed and the lab’s current backlog. Build this lead time into procurement schedules for time-sensitive or critical projects.

What’s the difference between a lab that offers AS6171 testing and one that’s accredited for it?

Any lab can buy the equipment and offer AS6171 test methods. Only a lab that holds ANAB accreditation under ISO/IEC 17025:2017 for a specific method has had its equipment, staff, and processes independently verified for that method. Unaccredited results may still be accurate, but they carry no third-party assurance and hold little weight in an audit, insurance claim, or regulatory review.

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