Chemical Etching Formula
Monel 400 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 Monel 400?

On Monel 400, 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 Monel 400 etch line runs a variant of this formula.

Process Window & Bath Control

Hold the bath at 50°C with concentration 44 °Bé (specific gravity 1.410). Across the 0.01-0.3 mm thickness range, conveyor speed runs from 0.17-59.88 m/min — thinner sheets move faster, thicker sheets slower, in roughly inverse proportion to thickness. A typical mid-range setpoint is 2.49 m/min for 0.05 mm stock. Use redundant PID temperature control to hold the bath within ±1.5°C, and titrate at least once per shift.

Design Rules & Tolerances

When laying out artwork for Monel 400 at through etch (double-sided), plan for a minimum hole diameter in the 8-360 μm range and a minimum line width in the 100-300 μm range, depending on the chosen sheet thickness within 0.01-0.3 mm. The etch factor of ~2.65 and undercut range of 1-57 μm determine how much the mask must be biased to land the finished dimension on target.

Yield & Production Economics

Typical mass-production yield for Monel 400 in the FeCl₃+HCl system is 96.3%, within an observed range of 95.6-96.5%. 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 Monel 400 processed with FeCl₃+HCl include battery tab interconnects, fuel-cell components, and corrosion-resistant masks. The formula's tolerance band and yield make it well suited to medium-to-high-volume precision flat parts.

Process Equipment & Material Reference

This Monel 400 formula is part of the standard process library running on our wet chemical etching machine. The same chemistry can be ported to any horizontal spray-etching line of comparable nozzle layout and bath-titration discipline.

For a broader treatment of the material itself — alloy variants, surface preparation, and process limits across thickness ranges — see our Nickel chemical etching guide. That overview complements the formula-specific bath and conveyor data on this page.

Production Use Cases for This Formula

Parts produced with this Monel 400 + FeCl₃+HCl formula end up in a wide range of finished products. Representative production runs we have completed using this exact recipe family include stainless filtration mesh for vacuum cleaners, electronic thin-film component etching, and cold-press juicer filtration mesh. Each case shares the same root sensitivity: clean photoresist edges, a tightly held bath SG of 1.410, and a conveyor speed inside the 0.17-59.88 m/min envelope.

If your part falls into one of these classes — or a closely adjacent one — this formula is usually the right starting point. We confirm fit with a short sample run on the actual sheet stock before locking in mask artwork.

Other Metals Etched with FeCl₃+HCl

The FeCl₃+HCl chemistry is also documented for these alloys.

More Pure Nickel Formulas

Other formulas in the same material family.

Frequently Asked Questions