Chemical Etching Formula
Inconel 601
with FeCl₃+HCl
Formula Summary
The table below summarizes every parameter that defines this etching formula. Values listed as ranges scale with sheet thickness across the supported band.
Why FeCl₃+HCl for Inconel 601?
On Inconel 601, the ferric chloride system attacks the alloy's oxide layer continuously while ferric ions drive dissolution. It is regenerable, compatible with standard photolithography, and produces clean burr-free edges — which is why nearly every Inconel 601 etch line runs a variant of this formula.
Process Window & Bath Control
The process window for this FeCl₃+HCl formula centres on 52°C and 46 °Bé. Conveyor speed spans 0.12-0.65 m/min over the 0.1-0.3 mm thickness band; the typical operating point is 0.21 m/min. Every 5°C drop in bath temperature requires roughly a 30% reduction in conveyor speed to hold the same etch depth, so temperature stability is the single biggest lever on consistency.
Design Rules & Tolerances
When laying out artwork for Inconel 601 at through etch (double-sided), plan for a minimum hole diameter in the 120-360 μm range and a minimum line width in the 100-300 μm range, depending on the chosen sheet thickness within 0.1-0.3 mm. The etch factor of ~2.50 and undercut range of 20-60 μm determine how much the mask must be biased to land the finished dimension on target.
• Minimum hole diameter range: 120-360 μm
• Minimum line width range: 100-300 μm
• Single-side undercut range: 20-60 μm
• Typical etch factor (EF): 2.50
Yield & Production Economics
Typical mass-production yield for Inconel 601 in the FeCl₃+HCl system is 94.9%, within an observed range of 94.6-95.2%. The dominant yield-loss modes are photoresist pinhole defects and rinse-water contamination. Improving incoming sheet quality and photoresist coating consistency gives the highest yield-improvement leverage for this formula.
Typical Applications
Typical applications for Inconel 601 processed with FeCl₃+HCl include turbine-engine seals, high-temperature gaskets, and aerospace fluidic plates. The formula's tolerance band and yield make it well suited to medium-to-high-volume precision flat parts.
Process Equipment & Material Reference
On the shop floor, this Inconel 601 + FeCl₃+HCl recipe is implemented on a wet chemical etching machine. The 52°C bath setpoint and 0.12-0.65 m/min conveyor range correspond to verified production envelopes on that equipment for through etch (double-sided).
If you need a wider view of nickel beyond this single recipe, our Nickel chemical etching guide covers grade selection, photoresist compatibility, and typical industries that consume this metal in etched form.
Production Use Cases for This Formula
Typical end-uses for Inconel 601 run on this formula include ultrasonic mesh for robotic vacuum cleaners, soy-milk-maker filtration mesh, and automotive horn mesh etching. The 52°C bath and 0.1-0.3 mm supported thickness range cover most of the production work in these segments without re-tuning chemistry.
Designs that sit slightly outside this thickness or feature-size envelope are usually addressable by a sister formula in the same etchant family. The bath chemistry stays the same; the tuning shifts to conveyor speed and resist choice.
More Nickel Superalloys Formulas
Other formulas in the same material family.
Frequently Asked Questions
Sources & References
- ASTM E407: Standard Practice for Microetching Metals and Alloys
- ASTM B912: Standard Specification for Passivation of Stainless Steels
- Photo Chemical Machining Institute — process capability guidelines
- NIST Engineering Statistics Handbook — process tolerance and capability
Standards are referenced for context. Always confirm parameters against the current published edition and your own process validation.
Need a Quote for This Process?
WET Etched runs production wet chemical etching lines using the FeCl₃+HCl chemistry. Send us your part drawing and quantity for a full process quote.