In most industries a part marking is a convenience. In aerospace and in medical device manufacturing it is a controlled process, written into the specification alongside dimensions and material. The question these industries ask is not only what the mark says, but how it was applied — because the marking method itself can either preserve a part or quietly compromise it. This is exactly where electrochemical marking earns its place, and why so many aerospace and surgical specifications name it directly.

Why the electrochemical marking method protects the part

Both industries share one hard constraint: the components are safety-critical and often fatigue-sensitive. A turbine disc, a landing-gear fitting, a bone screw, a surgical clamp — each spends its life under cyclic load, corrosive exposure, or repeated sterilization. Any marking process that adds mechanical stress, heat, or a surface defect becomes a potential crack-initiation or corrosion site.

That single fact separates the available methods:

• Dot peen and stamping deform the surface. They leave indentations that act as stress risers and, on instruments, as crevices that cannot be fully cleaned.
• Laser marking is non-contact but thermal — it creates a heat-affected zone (HAZ) that must be controlled, and on stainless instruments it can affect the passive layer if not followed by matched passivation.
• Electrochemical marking is neither mechanical nor thermal. A low current, an electrolyte, and a stencil etch the design through a controlled electrochemical reaction. There is no HAZ, no residual stress, and no raised or deformed surface.

Because of that, electrochemical marking is the method that most easily satisfies the “do no harm to the part” clause built into aerospace and medical standards — particularly on titanium, Inconel, nickel alloys, and thin-wall sections where fatigue life is the whole game.

Aerospace: standards that name electrochemical marking

Aerospace and defense marking is governed by a stack of overlapping standards. Electrochemical etching is recognized as an accepted permanent marking method across them, provided the finished mark meets the depth, contrast, and durability the standard requires. The core references a supplier is likely to meet:

• MIL-STD-130 — the US Department of Defense standard for Item Unique Identification (IUID) and traceability marking. It lists electro-chemical etching alongside laser and dot peen as an acceptable method for producing permanent human- and machine-readable marks.
• SAE AS9132 — the process and quality standard for 2D Data Matrix codes on metallic parts, issued through the International Aerospace Quality Group and referenced directly by MIL-STD-130.
• AS9100 — the aerospace quality management standard, which requires traceability from raw material all the way through delivery. Permanent serial and lot marks are how that traceability is physically carried on the part.
• SAE AS478 — identification marking methods for components and parts.
• NASA PRC-9003 — requires that marks be placed in low-stress areas where fatigue cracks are unlikely to propagate, which is precisely why a low-stress method is preferred in the first place.
• OEM specifications — prime and tier contractors publish their own approved-method specs that call out electrochemical etching, including Boeing BAC5307, Parker Aerospace BPS 4106, GE P23TF3, and Sikorsky SS8798.

It is worth being precise about what “required” means here. These standards mandate an outcome — a permanent, legible, verifiable mark that does not degrade the part — and they accept electrochemical etching as one of the qualified ways to reach it. On fatigue-critical and thin-wall components, where a stress-free surface is non-negotiable, it frequently becomes the preferred choice rather than merely a permitted one. As always, the shop validates its specific process against the applicable contract or program spec.

Medical: sterilization, corrosion, and the UDI mandate

On the medical side the driver is regulatory and biological at the same time. Two things must be true at once: every device has to carry a traceable identifier, and that identifier has to survive years of aggressive reprocessing without becoming a corrosion or contamination risk.

The regulatory layer is unambiguous:

• FDA UDI rule (21 CFR Part 830) — requires a Unique Device Identifier on medical devices, applied through direct part marking on devices intended for reuse and reprocessing.
• EU MDR 2017/745 — carries an equivalent UDI obligation for the European market.
• ISO 13485 — the quality management standard under which the whole marking and traceability process has to be documented and controlled.

The materials-and-surface layer is where the marking method is decided:

• ASTM F86 — the standard practice for surface preparation and marking of metallic surgical implants. It explicitly covers chemical and electrochemical surface treatments, and it addresses the sequencing question directly: a mark may be applied before or after passivation, with the marked area evaluated afterward to confirm corrosion resistance is intact.
• ASTM A967 / AMS2700 — passivation of stainless steel to restore the chromium-oxide passive layer that resists corrosion through repeated autoclave cycles.

The practical case for electrochemical marking on surgical instruments follows from this. Instruments are typically 304, 316L, 410 or 430 stainless, or titanium, and they endure hundreds of steam-sterilization and cleaning cycles. A marking method that removes no bulk material and raises no surface actually works with the passivation step instead of against it — the same electrochemical family of processes that ASTM F86 relies on for surface treatment. Compare that with a mechanical pin-stamp, whose indentations create pockets that cannot be reliably cleaned or sterilized. On instruments that go inside patients, that difference is not cosmetic.

The serialization problem — and why the stencil matters

Traceability standards do not ask for one repeated logo. They ask for a unique mark per unit: an incrementing serial number, a lot code, a 2D Data Matrix that encodes the enterprise identifier, part number, and serial. That is variable data — every part gets a different stencil.

This is the point where a marking programme succeeds or stalls. Producing a fresh, sharp stencil on demand — one per serial number, one per data-matrix — is what makes electrochemical marking viable for real production traceability rather than just for a fixed logo. A capable stencil printer, loaded with enough tape to run long uninterrupted batches, turns “unique mark per part” from a bottleneck into a routine step. For aerospace MRO and for medical instrument serialization, throughput on the stencil side is what keeps the whole line compliant and moving.

The takeaway

Aerospace and medical standards do not simply permit electrochemical marking — they are written around the exact properties it delivers: a permanent, legible, verifiable mark applied without stress, without heat, and without damage to a fatigue- or corrosion-sensitive part. Where MIL-STD-130 and AS9132 demand durable IUID marks on flight hardware, and where FDA UDI, EU MDR, and ASTM F86 demand corrosion-safe identification on surgical steel, electrochemical marking is the method engineered to say “yes” to both the identification requirement and the do-no-harm requirement at once.

If you mark parts for either sector and want to see how a compact electrochemical system with a high-capacity stencil printer fits a serialization or MRO workflow, our EUmark sets are built for exactly that job — get in touch and we will match a configuration to your throughput and your specification.