Burr-free, stress-free precision etching of thin metal parts.
Argent offers photo chemical etching (PCM) — also called photochemical machining, chemical milling, or chemical etching — for thin metal aerospace and defense parts that demand burr-free edges, no mechanical stress, and tight tolerances on complex 2D geometry. Stainless, titanium, beryllium copper, Inconel, and copper alloys in thicknesses from 0.001 to 0.060 inches.
How photo chemical etching works.
Photo chemical etching (PCM) is a subtractive metal-forming process that uses photoresist masking and chemical etchants to remove material from a metal sheet, leaving behind the desired part geometry. The process steps:
- Photoresist application. Both sides of a clean metal sheet are coated with a UV-sensitive photoresist film.
- UV exposure. The part geometry is photographically transferred to both sides of the sheet using a photo tool (similar to a photographic film negative).
- Development. The unexposed photoresist is removed, leaving a protective resist layer only on the part features that should remain.
- Etching. The sheet is sprayed with a chemical etchant (typically ferric chloride for stainless, hydrofluoric mixtures for titanium). The etchant dissolves the exposed metal but doesn't touch the resist-protected areas.
- Stripping. The remaining photoresist is removed, revealing the finished part.
What makes PCM the right choice
- Burr-free edges. No cutting tool means no mechanical burrs. Parts ship ready for assembly without secondary deburring.
- No mechanical stress. The metal experiences no cutting force, no heat-affected zone, and no work hardening. Material grain structure is preserved exactly as it was in the sheet.
- Thin-section capability. Parts as thin as 0.001 inches are routine. Conventional machining destroys material this thin.
- Complex geometry at low tooling cost. The photo tool is essentially a printed pattern, costing $100-500 versus $5,000+ for stamping dies. Design changes are fast and cheap.
- Identical parts in arrays. Hundreds or thousands of parts can be etched simultaneously from a single sheet, with no per-part setup.
Photo chemical etching specifications.
Materials we etch
- Stainless steel (304, 316, 17-7 PH, 17-4 PH) — the most common PCM material. Excellent etching response, dimensionally stable.
- Titanium (CP grades, 6Al-4V) — aerospace thin-sheet applications. Uses HF-based etchants.
- Beryllium copper — aerospace electrical contacts, springs, EMI shielding.
- Copper, brass, bronze — RF shields, antenna components, electrical contacts.
- Aluminum (most grades) — lightweight aerospace components, EMI gaskets.
- Inconel and Hastelloy — thin-section high-temperature parts.
- Invar 36, Kovar — thermal expansion-matched components, satellite electronics.
- Molybdenum, tungsten — refractory applications.
Typical PCM aerospace applications
- EMI / RFI shields and gaskets — satellite, avionics, ground station equipment
- Aerospace flexures and springs — precision mechanisms, sensor mounts
- Burst disks and rupture disks — pressure relief in propulsion and pneumatic systems
- Heat exchanger plates — thin-sheet stacked exchanger geometries
- Encoder wheels and reticles — aerospace instrumentation
- Filter screens and meshes — precision filtration in propulsion and hydraulic systems
- Antenna components — thin-sheet RF parts for satellite and avionics
- Shim stock and gaskets — precision-thickness laminations
Where PCM is the right answer over stamping, laser, or wire EDM.
Buyers often arrive at PCM after trying other processes that don't work for thin-sheet aerospace parts. Here's when PCM wins:
PCM vs stamping
Stamping is faster and cheaper at high volumes (10,000+ parts of identical geometry), but stamping requires expensive hard tooling ($5K-$50K+), produces burrs that require secondary deburring, and induces mechanical stress that can change material grain structure. PCM has $100-500 tooling cost, no burrs, and no stress. PCM wins below ~5,000 parts or when burr-free / stress-free is required.
PCM vs laser cutting
Laser cutting works well for one-off parts and prototype runs, but laser cutting produces a heat-affected zone (HAZ), recast layer, and small mechanical burrs from the assist gas. PCM has none of these. PCM wins when edge quality matters, when the heat-affected zone would compromise function, or when production volumes are high enough to amortize the photo tool.
PCM vs wire EDM
Wire EDM handles thicker material and tighter tolerances than PCM, but is significantly slower per part and produces a recast layer that can require secondary processing. PCM wins on thin material (under 0.060 in) and when production volumes make wire EDM cycle time uneconomical.
PCM vs waterjet
Waterjet is fast for one-off thin-sheet parts but produces tapered edges, mechanical burrs, and a wider kerf than PCM. PCM wins on small features, complex geometry, and production volumes.
Pairs well with.
Argent customers typically combine multiple capabilities on the same program. These are the most common pairings with this work.